It could be a plugin – possibly one left over from an extra that was removed. You can try selectively disabling plugins by right-clicking on them in the elements tree. Clear the cache after disabling each one before testing.
Do you mean temporarily or as a permanent solution?
I’m pretty sure it’s PHP 8 issues, as I never had these kind of errors in the same environment but with PHP 7. I don’t know if it’s a good idea to keep using an EOL version?
Or will these errors cause any more issues than filling my error log?
@vibedesign It’s your call, entirely. I haven’t gone to PHP 8 yet just because I don’t have time to deal with issues like the one you have. It takes time to make sure the error messages don’t indicate a serious problem somewhere, and try to track down a solution. YMMV.