@Robg10 

Hi,
Usually, the DecoBE65 and X10 can work together. In your situation, please refer to the instructions below to troubleshoot if a satellite Deco is unstable.
Fix unstable connection when connected to the Deco network
 

If the same phenomenon persists, please confirm the following information.
  1. When the Deco X10 goes offline in the Deco app, what's the LED status on it?
  2. When the Deco X10 is working, please go to the Deco app > Home tab > tap the Deco X10 and click on it again, then send us a screenshot of its page.
  3. Please try to swap the Deco X10 and another satellite Deco, then check if the Deco X10 still keeps going offline.

Best Regards