"server's IP address does not match certificate" when "Connect To" is a DNS-address, but, it seems, ROS does IP-address match instead of DNS-address match with certificate.

Are you talking about SSTP?
Certificate contains DNS name and you have sstp client with latest routeros version where you specify DNS as connect to address?

Are you talking about SSTP?
Certificate contains DNS name and you have sstp client with latest routeros version where you specify DNS as connect to address?

1) Yes.
2) Yes.

Certificate "Common Name" = DNS name of a server. Windows clients have no problem with this setup.

Currently such feature is not implemented for Mikrotik sstp clients. We will add in in the future.