Wyse ThinOS client will not work with RDS Gateway iAPP

Looking for some guidance here. We've setup an RDS 2016 farm and when I've used the RDS Gateway iAPP and set the F5 to use APM and proxy requests it works perfectly for Windows clients (using either the web access or mstsc).

 

However from our Wyse ThinOS devices they get the initial login and I can see they enumerate the desktops we're delivering via RDS. However when I click on one it then brings up the Terminal Services Gateway login box and will not accept any credentials.

 

To get the clients working I have to reconfigure the iAPP not to proxy the connections and instead SSL bridge to a Microsoft RDS GW server. The Wyse ThinOS devices then connect without a problem so it appears to be a problem within the F5 side.

 

Anybody else got the F5 to act as the gateway with Wyse ThinOS devices?

 

Thanks

 

Mark