Problem accessing rdp target in spp-sps joined environment

Hi everyone, i have a problem with my SPS-SPP joined system.

I set up the rdp connection settings towards a win server target, but whenever I make the request for that machine, once i start the rdp or download the file, it asks me to enter the password, even though i haven't specified in the settings the 'user supplied' parameter for the account password. Furthermore, if i manually inject the account password when it is asked, it reports that the password is incorrect.

Can anyone help me please? Thanks so much.