@ChrisRW I factory reset all 3 Deco M5's which ultimately removed my network, I then physically moved the main Deco M5 from the study to the hallway, the hallway M5 to the bedroom and the bedroom M5...

@David-TP I'll give this a try and will let you know within 48 hours to see if this fixes the problem.

I have 3 x Deco M5's connected to my Home Network. One is hardwired to my ISP's Router/Modem the 2nd is in the hallway (about 6 Meters away) and the 3rd is in the 1st floor bedroom about 6 meters...