Sims 4 fullscreen mode keeps minimizing

I honestly did nothing with the new account other than start Sims as soon as I created it. I didn't even start with a clean boot. I played for an entire day with no problems, and pretty much resigned myself to just playing on an alternate account if that's what worked, put the computer into hibernate for the night and picked up the next day. It was running fine for several hours then in the middle of playing, the game suddenly minimized. Nothing else was open, not even origin. Then when I tried to open it from the taskbar, the problem started up all over again. Restarting the game did nothing to fix it and repair didn't either, and I didn't restart my computer.

@Maasterash  In the new account, please try disabling all notifications under Settings > System > Notifications.  Specifically do it in this order: first, turn off the notification for each individual app, then all the check boxes above the apps list, then the global setting.

If that doesn't help, please post a screenshot or two showing all the apps listed in Notifications.

Notifications are some of the first things I turn off, honestly. not a single app or browser has them on. When the game minimizes, nothing actually pops up, it's just that I can't keep it open.

@Maasterash  I'd still like to see the list of apps that would want to generate notifications if you allowed them.

Additionally, have you tried uninstalling GeForce Experience?  It would be odd for it to have this effect on Sims 4, but even with the overlay disabled, it could still be interfering.

I haven't reinstalled Experience since uninstalling and reinstalling my drivers, but I never let it optimize games I play because it wants to run them in the wrong resolution. Also whenever I play any games I try to make sure nothing at all is running because I'm always concerned about PC temps and good performance with highest possible graphics. There's not many apps on my computer that show up for notifications, and the only one I actively use, discord, is also closed whenever I play (completely shut down, not just minimized).

@Maasterash  This is kind of a long shot, but try playing with no internet connection.  You can sign into Origin and put it in offline mode, then disable wifi and/or disconnect the ethernet cable before launching Sims 4.  You should be able to open it from Origin, but in case you can't access your game library, double-clicking the .exe or its shortcut should still work.

I gave up on trying to fix it for a few days and when I went back, it's completely stable again. Other than one infinite saving screen and a crash(from a lot with too much on it from the gallery), there's no problems anymore. I have no idea what is causing this or if it will come back, but I hope not.