Hello, I haven't seen any differences for this connection issue between epel repo 1.5.5 and compiled from source on the same system.
I've done some more testing on this issue and for RDP connection parameters, if username and password are not specified and security is set to blank or 'any' the connection fails instead of landing the user on the login. If username and password parameters are specified, the connection works. If the security parameter is specified as 'tls' the connection works as expected with and without username and password, and is what we are now using. For us, this is a behaviour change from 1.4.0 where previously 'any' was specified and would work as expected in cases with and without username and password. If anyone is having this issue with RDP connections and is using 'any' as the security parameter without username and password, try changing it to 'tls'. Regards