Some players report that when they launch the game they get mini freezes (< 1 second) every few seconds (~2) for up to 5 minutes after launching the game. It also occurs when no mods are running.

And this problem doesn't happen when they launch the game (and Steam) offline.

I personally don't have this problem but since I didn't find anyone reporting it here (they simply complain about it on Discord) I decided to at least make a ticket for further investigation.

Since the problem occurs when the users are online, I guess it is related to one of these:

1. BattleEye
2. Steam Updating in the background (though people said this wasn't happening when they were running the game)
3. DLC "Ad"
4. A3 units

In my case (where problem doesn't occur), I:

1. don't run BattleEye
2. have all DLCs
3. don't use A3 units

So I guess any of them can be a valid cause of the problem.