Often, the "Relay" happens because Windows Firewall is blocking the UDP hole-punching attempt required for a Direct connection.
For issues, Radmin’s protocol may be incompatible with your network. Use these instead (both support P2P): radmin vpn relay tcp fix work
If your definition of "TCP Fix" refers to rather than fixing the Relay issue, here is the review for that approach: Often, the "Relay" happens because Windows Firewall is