Hi Morgan! So this issue is due to Squad itself and how it loads up mods. Squad will load up the mod, however fail to setup modded factions correctly resulting in an "async load fail". This is why you can load into a server without a "file mismatch", yet as soon as you join the server you can't reach the team select page.
The issue generally stems from players having Squad installed on a HDD or a portable SSD, I wish I knew the specifics on to why this is the issue but our best guess currently is mainly the reading speed. The best thing to do is to move Squad, using steam's relocation feature for games, from the HDD to a SSD.
If you only have a HDD, it's not impossible for you to play, it just a lot harder. The best we can do is give you some suggestion to help minimize this error from occurring. As always you can join the discord.gg/galacticcontention and we'll more than gladly to answer more questions or concerns there.
---- LIST OF POTENTIAL FIXES ----
While the fixes provided by our standard infinite loading screen issues work for many, this process is a more robust guide to fixing the "infinite running man" or infinite loading screen error. This issue mainly is the result of how Squad loads mods and is unable to load in small details like factions, causing it to halt you when attempting to load into the server due to it believing you haven't finished loading in all assets. This issue has been occurring in mods for roughly 4 years now and even occurred to Squad's Canadian Forces DLC before being integrated into the main files.
If the issue still persists, need assistance on certain steps, or you find a possible solution towards this issue, please contact the staff team in discord.com/invite/galacticcontention , we are here to help you and want our community to have fun and be able to enjoy this awesome mod made by the developers!

- List provided by GC Tech Support Staff team and additional assistance by the GC Community and modding community!
0) Wait till modded faction icons appear in the server description in the browser.
The easiest and quickest way to spot this issue before even joining the server are the modded faction icons displayed in the server description for server(s) running the mod. If you attempt to join the server before they appear, you more than likely will run into the issue as Squad hasn't fully loaded in data from the mod. Let it sit for 3-7mins and repeat this every time you try a new step. Additionally, refreshing the page can also make them appear after X amount of time.
1) If possible, ensure Squad is installed on an internal disk drive (Preferably SSD)
Installing Squad on a SSD generally helps with loading in the mod faster allowing you to see faction icons faster or easier. HDDs are great however are generally slower than SSDs, and for some reason Squad tends to be bias against HDDs. It’s even more apparent if you have an external SSD and/or HDD, as they seem to struggle more compared to internal drives. We HIGHLY recommend using internal drive if possible unless you have a type-c connection. HDD If you don't have a SSD, fear not! HDDs **CAN WORK**, it is not a lost cause. Just understand it might be alot harder and frustrating but we'll get through this!
2) Clear Squad Cache
Squad Cache can be located in the main menu settings at the very bottom of the screen. **CAUTION** THIS WILL RESET YOUR KEYBINDS AND SETTINGS! If you want to save these settings, join the discord and we have a possible way to save them!
3) Close background applications, put settings on Borderless or Window, reduce resolution and Relaunch Squad without Alt + Tabbing
This step is to try and ease how much your PC needs to work booting up the mod. Helps reduce the amount of things in the background and graphically how much Squad needs to boot up.
4) Clear Download Cache In Steam
Clearing steam's download cache can help with game's boot ups issues. To access it, open the steam client -> Steam at the top left -> settings -> downloads -> Clear Download Cache
5) Restart PC
Restarting the PC might help if there was a possible error in its bootup causing performance issues. It's not common but still a possible factor.
6) Disable background software applications + Update Drivers
When contacting OWI, they stated a common case were background applications like Razer Synapse, iCUE, Armorcrate, RGB lighting applications etc. Disabling some of these applications can help with issues affecting Squad. To see what applications might be running in the background: On your taskbar in the desktop screen, look towards the bottom right with an upward arrow ( ^ ), it will display all applications currenting running in the background and possibly hidden. Disable or quit unnecessary applications.
In addition it’s always best to keep your components up to date as they might cause issues in the long run.
7) Uninstall unwanted or non-updated mods
This is an old issue and uncommon catalyst, yet not impossible. Back then mods had the possibility of conflicting and causing one or both to have issues until one was uninstalled. For the most part OWI has fixed this issue.
8) Manually Clear Squad Cache, Delete SquadGame File
Essentially the same step as step 2, yet if you wish to manually clear it, you can head over to the file location and delete it.
Go to your C drive (M.2 SSD) -> Users -> (PC/Account Name) -> AppData (Might need to view hidden items, can be done under view tab and click on the square box) -> Local -> SquadGame
Delete SquadGame file and reverify game files in the steam client
9) Run Steam as Administrator
Right click on Steam in the desktop (if from the taskbar, you may need to right click steam twice) and select "Run as administrator"
Launch Steam and Squad
10) Run Squad as Administrator
Similar to step 9, yet we will be running the game as administrator
To find Squad_launcher, inside Steam right click on "Squad" -> Manage -> Browse Local Files -> Click on File Explorer and Click Squad_launcher (the icon or the name) and Run as Administrator
11) Restart PC and Run as Administrator (Either do steam or Squad_launcher, or both)
Essentially a combination of step 9 and 10 with the addition of restarting your PC.
Step 11.5 New: As in Step 10, find the file location for Squad and navigate to SquadGame -> Binaries -> Win64 -> Right click on SquadGame.exe -> properties -> compatibility -> check “Run this program as an administrator”. Do step 10 again
12) Adding a string code in Engine.ini
Another possible fix recently discovered to the Infinite Running Man bug on HDDs would be to manually load the mod files while the game is loading - this fix is heavily experimental so your mileage may vary. This was an old way OWI attempted to fix the loading issue with the CAF DLC
1. Navigate to %localappdata%\SquadGame\Saved\Config\WindowsNoEditor and open Engine.ini OR follow file locaiton
C:\Users\PC Name\AppData\Local\SquadGame\Saved\Config\WindowsNoEditor
2. add this string Paths=../../../../../workshop/content/393380/2428425228/ANE_BASE/Content
to the end of the [Core.System] section
3. Save/close the file, launch the game, and attempt to connect
Your paths may also vary if you installed squad outside of the default SteamApps folder, but the just of it is to add a Path to the mod content folder within the Engine config
`13) Repeatedly Clear Squad Cache Data`
You can repeatedly clear Squad cache from step 2 till it works.

--Ending Statement--
This is the end of our list of possible solutions as it stands. As previously stated, if this list hasn't worked for you, please join our discord! If we find a solution, we post it in an open thread for all to see. We know many people suffer from this frustrating issue and it can be just a matter of luck to get it to work or coming back to it another day. We wish this issue was much simpler than it is to resolve yet it is something we unfortunately can't fix ourselves and is out of reach. We want everyone interested in GC to be able to enjoy the mod and get into the battlefield ASAP! I'll try to update this report whenever something new arises or a new solution is found. Best of luck trooper and hope we were of help towards your technical issue!
- Written report by GC's tech support and admin
[GC] Dustiercorn

Edit log:
10/15/2022: List V1 created! Will attempt to update this list when possible
11/04/2022: Added Step 11.5, in trial
11/14/2022 Specified step 1 to put game on internal disk rather than externals
11/19/2022: Specified step 0 to be applied through all steps and a rough time frame
12/05/2022: Included players to refresh page after waiting for faction icons to appear if not appearing

Sum bs all I gotta say.. they need to fix this on their end.. it only started commonly happening back in December

This mod is ♥♥♥♥, but I'll play it anyways.

how the ♥♥♥♥ is buying a ssd the only solution to this?

Originally posted by Potato:

how the ♥♥♥♥ is buying a ssd the only solution to this?

Yep :(

Originally posted by Potato:

how the ♥♥♥♥ is buying a ssd the only solution to this?

It's currently the solution that's worked almost every time. Like I stated in the text "wish I knew the specifics on to why this is the issue" but we're constantly talking to OWI about this issue as at the end of the day we want you guys to be able to play and enjoy the mod. OWI losses players this way and is an issue that needs to be fixed ASAP, hopefully in an upcoming update we'll see it in the patch notes and be able to push this issue behind us.

works everytime huh, fix your mod

Originally posted by ArmorForSleep:

works everytime huh, fix your mod

ArmorForSleep, SSDs unfortunately still can get this issue but generally not that often hence the "**ALMOST** everytime"
On SSDs you may sometimes need to clear Squad cache or steam cache in order for it to work. Hell restarting your PC has fixed it for some as well.
If the SSD is portable, for some reason they are affected (an issue we are still looking into, possibly related to it being old gen USB)
And as stated in the explanation of what occurs " this issue isn't something we can fix as mod developers, only OWI (creators of Squad) can fix it."

followed the instruction to the letter still shows no server plus i have SSD

Originally posted by LukeKuza:

followed the instruction to the letter still shows no server plus i have SSD

That's because the mod is not up to date with the latest Squad update. We just got the SDK update a few hours ago. It will take some time for the developers to get everything back and running, but we will try our best to keep everyone posted in the discord and in the workshop comments/discussions.
Till we update the mod, the mod will not work in Jensen Range or private servers.

What a load of bs debug your mod ffs

Originally posted by Ethanen:

What a load of bs debug your mod ffs

Go ask MEE and other mods with modded factions , they get the same issues

clearing in-game cache has worked for me!

For HDD just close the game and retry

or merge Game + Workshop mods into a SSD or SSD NVME

In my case, i used to get the infinite loading screen. One way i "fix" it is clearing the game's cache when i initially first run squad. When i run it a 2nd time, i set it to full screen and enter the GAL server. This method is a bit odd and slightly time consuming, but it hasn't done me wrong yet. This also applies to other mods such as middle east escalation. Hope this somewhat helps