TCP or UDP?

TCP or UDP?

We are troubleshooting an unusual problem in implementation of PAM360 in our Enterprise. Some servers cannot be reached with RDP while using the Web interface of PAM360. However, these servers are reachable if tested from the PAM360 server, logged in interactively using the desktop RDC app. Trying to narrow down the cause, and it occurred to me that the desktop app defaults to UDP, but falls back to TCP. Do PAM360 initiated RDP connections use only UDP, with no fallback to TCP?