This appears to be a bug affecting the latest version of Safari. We don’t control the QuickType UI and can only provide suggestions to it. We're hoping Apple will release a fix soon!
The only thing we can recommend at this time is to keep installing any available updates for Safari and macOS.
You should still be able to select Strongbox... in order to navigate and AutoFill your passwords:
If you're interested, there's an open issue on Github for this problem: https://github.com/strongbox-password-safe/Strongbox/issues/695#issuecomment-1505010525
May 9, 2023