Or alternatively, switch to a different web browser that is still receiving regular updates on Catalina.
Firefox requires 10.12 (“Sierra”) or later, so that’s one option.
Microsoft Edge requires 10.13 (“High Sierra”) or later, so that’s another option.
Other browsers have other minimum requirements, which may be compatible with Catalina.
Recent experiences of it still happening, with lesser accessed networks, lead me to think it might be connected with the introduction of the ability to reveal a WiFi password?
(Although they were always stored in the keychain, and could be retrieved on a Mac ever since the introduction of iCloud Keychain.)
Regardless, it’s still very annoying.
This doesn’t mean that there isn’t some sort of bug, but I’m not seeing that at all. I haven’t all through iOS 16.
I know it can be a pain in the neck, but have you tried resetting network settings? Settings / General / Transfer or Reset phone, tap “Reset” at the bottom, tap reset network settings.
This will forget all WiFi network passwords, but if you’re having an issue with network settings, this would be the first step to solve the problem.
I’m just re-entering them as I encounter them, those remaining will be places I visit less often. It does remember them afterwards, whereas if I were to reset network settings now I’d definitely have to reenter them, including those already done.