5400T not sharing XM with 3500EM

[Cojaken]

I have a 5400T PFD and a 3500EM non-S. Both have the latest available system software and map files.

My XM weather, which comes from a WxWorx receiver will display on whichever of the two screens I configure as the Wx Master, but not the other one. Also, when I configure the 3500 as "Slave" the screen display "XM-WX offline".

The screens are communicating via an Ethernet hub and both showing air and engine data. The WxWorx is also communicating via the Ethernet hub.

I did briefly try to configure both screens as Master and this appeared to work initially, but was unreliable after power cycling the screens.

I have re-posted this question in a new thread with a more meaningful title, in the hope of attracting attention.

Any suggestions please anyone?