Wyse ThinOS 9.1.5067 and RDP issues

Hi, 
I've currently deployed a new WMS 3.5.2 to a remote site to try and fix the many connection issues they are having with the 9.0+ ThinOS Wyse terminals. 

The 8.6 and below terminals are perfectly fine, and if I could physically get my hands on them I would upgrade all the 9.0+ ones to 8.6.

I've configured a RDP sessions in WMS and almost all settings do get pushed across, apart from running the session in Fullscreen or in a Window.  This setting does not seem to be getting pushed from WMS, I can set it on the terminal manually and it then connects fullscreen.

A second issue is that RDP session on terminals with two screens are now connecting and using both screens as one spanned screen as opposed to two discreet screens in the RDP session.  Which settings do I need to change for this to work correctly again?