It will take some times more before app providers will catch up with the new android, so many apps are not going to work. This is a new operating system and developers will need time to provide updates to their apps.
I reported this to Fidelity and Samsung yesterday. Fidelity already responded to say they are aware and working on the issue. Unfortunately no fix date at present.
The Fidelity app was broken on Android 11. I could install it, but when logging in to my Fidelity account I got an error that there was no internet connectivity. It was just with the Fidelity app. All other apps had internet connectivity.