While going through the MySQL logs from a DO instance, I found the following entries:
2020-06-04T08:14:44.965714Z 2 [Warning] Hostname 'rnd.group-ib.ru' does not resolve to '18.104.22.168'.
Hmm this does look troubling. Usually, this doesn't give out IP addresses unless specifically told so. I'll recommend to check your whole log and see if these IP addresses occur on other lines of the lo...