A couple of things: I have a few apps that won't even open because I'm waiting on the app developers to get their act together and update their apps. On a different post I saw where the My AT&T app is creating problems after AT&T released the update. It happens. As to your mobile banking apps, as long as you can still log in (PIN, password) you at least have access and are only inconvenienced for the moment. Try to uninstall/reinstall those apps and see how that works. Read the reviews on the Google Play Store for the apps in question. Others may be having the same problem as you after the update.
According to many on this board, it's a good practice to wipe your cache partition and repair apps after any software update (not to be confused with monthly security patches). I do this each time and it helps. Good luck.
Yeah I have a Samsung Galaxy S21 Ultra 5G TMobile network Unlocked version. I updated to One UI 4, yesterday and I'm having lots of issues in opening banking apps. Wells Fargo don't even open. I just crashes. I have a WhatsApp in dual mode and I can't send any images. I'm sure there are more issues. I just haven't found a all the bugs yet. Hopefully Samsung can release a fix soon .
