The whole issue is really weird. I can launch the server just fine. When I start the launcher, it gets stuck on "Connecting" and after that, I get the message "Default server SPT-AKI is not available".
THE CRUCIAL THING IS it only happens when my main profile file is in the "Profiles" folder. When I remove it and use for example a different profile (old or new) the launcher works fine, I can log in, start the game, start a raid, finish it, trade etc. However, when my main profile file is in the folder alongside others, I can't log to either (it also gets stuck on "Connecting").
Another thing I can't explain is the fact that I got this bug almost a month ago. I got back to AKI this week and all of a sudden everything works fine. It actually worked fine for a few days, then the same issue for a day. Then the next day the problem is gone for almost a whole day and now is present again.
That's why I suspect something is wrong with my profile alone. The thing is I am using Adrudis Quest Maniac so I have already started and finished a huge amount of quests. Also after many hours, I have really A LOT of stuff in my stash (something like 9 full Scav Cases and a ton of other containers with gear and loot). Could it be the case that my profile file is too big and causes issues with the launcher? It doesn't however explain why the problem could come and go a few times already since my stash got even bigger along this time.
Other suspects are dynamic values like fuel in generator or Flea Market prices.