OperationalError: sorry, too many clients already

Apparently, per what I wrote in this thread, connections are closed in a close method (that I linked in the thread) if CONN_AGE_MAX is 0, but are closed “somewhere else” otherwise. I posted a report of what I observed so far in that thread. Do you have an idea where the connections opened with a CONN_MAX_AGE value greater than 0 might be being closed at?