@Marvin_S Thanks for your advice Marvin. I've just swapped the 2 Decos and will wait to see what happens over time. For information, the signal between each Deco is indicated as “average”, two green...

In a fairly long building, I have 3 Deco M5s in line. The main one at one end of the building, the second one in the middle and the third one at the other end. The one in the middle regularly (two or...