@yves_b Thanks for the swift response. I disconnected number 3 and tried again in it's intended position. It went Red, like before, but I was distracted and left it for a while. When I returned, it...

My mesh set up is limited by the primary M4 being in ine corner of the house. The next one is 8 metres away in a hallway, with the final M4 untended for a bedroom a further 4 metres beyond that. The...