I ran into this problem about a month ago. Tried a bunch of different things to get POP to work again but never was able to get it going again -- finally resorted to changing ti IMAP. I spent a fair amount of time googling and tried a bunch of suggestions. Hopefully someone has an answer for this as I prefer POP3 or IMAP too.

Might make sure you have this done...
https://support.google.com/googlecloud/answer/10661442?hl=en#:~:text=If%20it's%20been%20a%20long,it%20is%20not%20already%20enabled.


>Hi,
>
>Since this morning, my Outlook does not connect to Gmail accounts.
>
>Currently my Gmail emails (in Outlook) are set to use POP/SMTP. Do I need/have to change it to IMAP?
>
>TIA