I am using Samsung Note 10 Lite with Android 11... after new version update my notes would not open... even those in downloaded notebooks...
1) I uninstalled app then installed old version 8.3 ... notes still would not open
2) I then updated app to new version 10 and now I am able to open my notes...
I am thinking uninstalling app then re-installing app is what worked for me... so I would suggest to others having problems with new version would be to uninstall app, restart phone, then install new version...
Good luck 🙂