I helped a friend set up their system of a Beam in the lounge and a Play 1 with an additional Echo Dot in a bedroom.

Initially I had an issue with a Wi-Fi extender, where the Play 1 was connecting to it, but not able to group with the Beam. Turned off the extender and re-connected the Play 1 and grouped as expected.

However, the Beam does not auto ungroup when the TV is turned on and you need to select from the App controller.

Could it be something to do with the extender which is primarily for other rooms further away from the main router.