well, technically changing DNS ips should not break existing AD integration and you should able to log-in to vcenter using AD account along with local account
I have not seen stating it in Known issues but don't worry
Thumb rule, revert to old snapshot [where no changes happened to vcenter] if you can live with using old DNS IPs
let me try something here from my side if I can replicate this issue
vcenter version is 6.7 U2 correct?