I'm seeing a device on Fing that is called DecoMeshXE5300" on my network that constantly goes in and out of range, but never connects. it is one MAC address above my main Deco router. Why is it there...

I've seen earlier threads about this, and it seemed to be resolved with a firmware update. But I just bought a new AXE5300 system and updated to the latest firmware, and still can't get it to work,...