Our cloud instance and agents were just updated on the 19th and since then we've had issues with RDP on almost all of our workstations and servers. We're not 100% certain it's the endpoint agent but we're not aware of any major updates or changes that took place across the board and when we booted a machine that hadn't updated, we were able to until the agent updated. 

After a lot of troubleshooting we found that running 'netsh winsock reset' & then restarting seems to fix the issue. 

When RDPing you get a "The login attempt failed" message. 

I've opened a ticket with support but curious if others have run in to this problem.