This is less of a question and more of information for other folks. 1Password seems to be working great on iOS 15. This includes both the app itself and using 1Password to enter passwords in the updated Safari.
Thanks for making such a solid app 1Password Team!
1Password Version: 7.7.6
Extension Version: Not Provided
OS Version: iOS 15.0 (19A5261w)
Sync Type: iCloud