@Ignasi Sorry it took so long to reply. I was trying to be thorough, and this required lots of rebooting, etc. Even with nvme ssds it still takes a bit. Note: Because I have 3 Steam accts I switch between, I have Steam set to launch at system start, but not to auto-login.
I can tell you that I 100% of the time see the advertisement reappear when the daily server reboot kicks me back to the menu on my first alt account, however I do not see it if I merely exit to the menu of my own accord.
Test case #1:
Booted PC.
Observed the last acct I’d been logged into on Steam was Alt #2.
Instead of logging in as Alt 2, I logged into Steam on my main acct (on which I own all DLCs, including the 1980s movie one).
Launched game, and I believe some mods I subscribe to wanted to update before I could play, even though I have all of them disabled since I play on an Official server.
Got advertisement screen.
Exited game.
Test case #2:
Relaunched game on the same account (main), did not reboot, did not sign-out of Steam.
No advertisement screen.
Exited game.
Test case #3:
Logged out of Steam.
Logged in again as same acct (main).
Launched game.
No advertisement screen.
Exited game.
Test case #4:
Rebooted.
Logged in as my main Steam acct again.
Launched game.
No advertisement screen.
Exited game.
Test case #5:
Stayed logged into Steam (main), opened workshop and subscribed to a new mod (Pippi).
Immediately launched game before download could complete.
No advertisement screen.
Exited game.
Test case #6:
Still signed in on main, waited for mod to finish downloading then launched game.
BattleEye crapped out with the Blocked Loading of File message twice. Launched on 3rd try.
No advertisement screen.
Exited game.
Test case #7:
Still signed into Steam (main), performed a Verify Integrity of Game Files.
1 file was reacquired (BaseInput.ini where I always have to re-disable mouse smoothing and F11 = fullscreen after an update).
Launched game.
No advertisement screen.
Exited game.
Test case #8:
Signed out of Steam, did not reboot.
Logged in as my first alt account (which owns everything but the 80s movie DLC).
Launched game, BattleEye crapped out once before launching game.
No advertisement screen.
Exited game.
Test case #9:
Rebooted.
Signed in as my second alt acct (owns everything but 80s movie).
Launched game.
Got advertisement screen!
Exited game.
Test case #10:
Rebooted.
Logged in as 1st alt on Steam.
Launched game.
Got advertisement screen!
So far, it looks like rebooting combined with switching Steam accounts is what’s triggering the advertisement screen to get displayed as that’s what happened in cases 1, 9, and 10.
Let me know if there’s any other combinations you’d like me to try, but hopefully this is helpful.