AT&T email account is blocking gmail messages again

I seem to be experiencing the same problem with my AT&T email account (a carry-over sbcglobal account) that I and many other users had back in December of 2023. Namely, all incoming email messages from gmail accounts are being blocked by the mail server altogether (or in other instances, take two days to deliver). As I recall, this was not a problem that individual users could address by adjusting anything in their settings, it required coordination between ATT and gmail/Google. If (as I assume) I'm not the only one experiencing this problem, who is a point of contact to speak to about it?

Thank you.