Safari Setting window not opening

My only other thought would be to try using "Safari > "Create Profile..." to get to the Settings panel. If that works, you may want to continue by creating a new profile to see if that resolves the settings display issue:

Use profiles in Safari on Mac - Apple Support

I did not know that the Safari safe mode was gone.

See the following post for instructions about booting the Mac in safe mode and then testing Safari. Safe mode clears caches on the Mac so if there is something odd cached it may resolve the issue:

preferences on safari disappear - Apple Community

Try holding shift key while launching Safari. That should bring it up in safe mode. Try the setting menu there. If it works, try disabling all extensions and then start it up regularly to test again.

My (newer macOS) Safari settings does not have the Passwords tab at all, but what about going to the "AutoFill" settings and disabling "Autofill web forms" > "Usernames and Passwords" > Disabled. Then, quit Safari, launch it again, re-enable that setting, test.

Other than that, I'm out of ideas. Hopefully someone more experienced with the Safari user interface will post a suggestion of if there is a preference file in your macOS 13.7 that may be at fault and can easily be deleted for a reset. There must be a way to "reset" the Safari user interface.

Try using the keyboard shortcut command+,

Hold down the command key while typing the comma key.

Any luck?