I upgraded to Ubuntu 22.04 and v61.1. It resulted in DANE TLSA record and MTA-STS policy errors, which persisted for over 12 hours.
At the same time, my website which is hosted on a different server, was failing to load. My mail server is at box.example.com and website at example.com, and I was pointing A, AAA and CNAME records to example.com from the MIAB web interface.
I deleted all three DNS records and readded them. Within a few minutes all errors disappeared on Status check, and my website started working.