I use quite an aging Xytel Multy X “mesh” system. 3 nodes from my Wifi Modem/router.
I see two networks broadcasted – one is the original Wifi Router Modem and the other is the designated name from the Multy master (which one unit is hard wired connected to the Modem/Router). All the Multy X broadcast the same wifi ID.
I connect all devices to the Multy X Wifi ID. All works perfectly and continuously across 3 floors and a stairwell.
I feel you need to configure your Mesh system to a similar setup. If you are using a number of old Routers (non-mesh), it is possible to get them in relay mode toggling the internal configuration. However, the BeoApp to me would not be the source of your problem here.