Your issue was fixed, and your community was working earlier today. You were also getting a lot of errors logged from a plethora of third-party things, likely some of them need updating.
Fatal error: Uncaught ErrorException: Required parameter $table follows optional parameter $columns in
This is a third party issue.
As noted, the reason it took us longer than usual to identify the issue was due to a server-side cache (that still appears to be active) that's caching all error responses, so even after the underlying error goes away, the error is still displayed to the end-user.
Fatal error: Uncaught Error: Call to undefined method IPS\Lang::recordWord()
This suggests a hook file is missing or not being loaded, you could disable and re-enable the Pages application to rewrite the hooks file and see if that fixes it.
It does look like you've switched to PHP 8.1 after the above issue occurred (not sure why), I would suggest switching back to PHP 8.0 and then toggling the application to rewrite the hooks.