I do not switch profiles that often. I am quite happy with the FOSS apps I have on my owner profile. The only time I switch my profile is when I need to make online transaction, using Google Maps, listening to Spotify or watching Netflix. Below are a few strange bugs I have faced after switching to the user profile. I do not notice these bugs everytime. They occur randomly and get fixed on heir own after some time.
After switching to the user profile, none of the apps wanted to open. As soon as I launched them, they closed immediately. It kept repeating for some time until It got fixed on its own. This happened with me on two different occasions.
Swiping down on the homescreen made the stock launcher (I don't have any other launcher) crash immediately and it kept repeating until I cleared data and cache from the launcher app. This also happened twice.
After leaving an app (no matter which app it is), it got removed from the recents immediately. This also happened twice and got fixed on its own after some time.
P.S. I made sure to install Google apps (Play Services, Framework and Play Store) as per the order mentioned on GrapheneOS guide. After facing these issues for the first time, I uninstalled and reinstalled again but still faced this issue again. They do not occur always so I am sure the issues are not related to Play Services.
Device model: Pixel 7a (lynx)