I tested this in creative. It seems the 300mm and 900mm cannons will only track and not shoot. I was able to get them to shoot after deleting the cannons and placing more. I hope this is fixed soon. In my survival, the 300mm single barrel works fine (if you use HE ammo, AP ammo doesnt work either)

So if I delete them and place them again they will work again?

It seems to be the case. I was able to do that in creative mode. But try it, but then test them to make sure by spawning a small ship and setting it to pirates and see if they shoot.

This bug is really annoying indeed. Hopefully the author fix this soon.

Agreed. It hasnt been updated since launch though sadly.

It seems like game bug, cause not only this mod works like that

Hey everyone I've fixed the reload bug and uploaded a temporary mod to the workshop which can be found here: http://gtm.steamproxy.vip/sharedfiles/filedetails/?id=647339298
All weapons seemed to be working and reloading properly again.