by Matteo Scaramuccia.
Hi Debbie,
TNX for sharing your issue and solution too: when working at MDL-60793 we believed people would jump to 3.5 via 3.3 or 3.4 - by updating first to the latest 3.3.x/3.4.y available and still working w/ MySQL 5.7 and then moving to MySQL 8 being then Moodle compatible with it -, but eventually we were wrong .
Could you give us more details on how you moved to MySQL 8.x running what version of Moodle before upgrading?
The more the better : I'm going to file an issue into the Tracker, including proposing a fix compatible with all the DB supported by Moodle.
HTH,
Matteo