If you are facing this error message when trying to RDP to a Domain-joined Server :
The connection cannot be completed because the remote computer that was reached is not the one you specified. This could be caused by an outdated entry in the DNS cache. Try using the IP address of the computer instead of the name.
1st to check is as told by the message; DNS configuration. Client-side and Server-side.
If that’s fine, the problem is elsewhere.
You should be able to connect using the IP address
using the Hostname but login with a Local Account instead of a Domain Account.
If I’m correct, your Server CLOCK is not Synchronized with your Domain. Simply Sync it using w32tm or modify it manually and try to connect.
Hope this helps.