so im not sure about INT and STR builds but DEX vulnerability artifact bugs after exactly 30 secs into combat and stops applying
this can be re-initiated simply by opening a menu, i have been using player stat menu or attribute page. simply click it open and close it again and vulnerability artifact will once again start to apply it to mobs including major bosses
since this is somewhat tedious i have just defaulted to an auto clicker sadly, each 28 secs it will open a menu and close it again in succession
for the most part its not really needed but for progression fights absolutly essential
devs are still very active so hopefully a fix will come soon


the second bug i came across was auto progression with my stage keys, i was having issue both on the on-screen toggle and then when the run would finish it still wouldnt progress even though the toggle was activated.
i had to go through all my game modes and switch all of the toggles OFF in order to get my stage keys to auto repeat successfully.
game modes i had to enter and turn off auto-progression and auto repeat were standard maps and challenge key modes.
after i turned ALL toggles to off my stage keys once again worked with auto repeat no worries
before trying those i had even checked my game files, cleared my cache and even did a complete reinstall none of which helped
since auto progression and auto repeat are very new mechanics im going to assume its still being worked on and since there is a long list of updates and fixes spread over the last several months i have high hopes which is nice since im kinda of addicted right now :)


so there also seems to be a bug with quests
while the game offers you to complete maps in any order it seems to cause an issue with quests being offered and since many quests offer gem rewards they are kind of critical particularly in early game.
daily quests generating also may be a factor in this.
my suggestion is to never skip any maps and target various stages in sequential order and hopefully the game will offer all of its much desirable quests
honestly there is plenty on offer, particularly if you succeed in proper game progression so missing a few wont really hurt you as much as is might seem and at the very least there will always be daily gem rewards so you can make up for it if the worst happens

just dont skip maps


finally a note on progression
there is a topic in here:
    
Tier 3 grind wall
by duke_of_silence 1 May @ 6:34pm

i have added a response in here to properly tackle this issue as it also caught me and i nearly quit since the game wont direct you on the proper course

hope this helps