@Ray072 Your Deco M9 Plus have the latest firmware, which is good. My plan would be to help you tune your Deco mesh performance and also see if it can operate without powerline adapters. I can't tell...

@Ray072 I have M9 Plus in my Deco mesh and may be able to help you troubleshoot and tune your Deco mesh. From your description the primary suspect for random disconnects would be powerline adapters....

@CCDan If you plan full Deco mesh restart, you can restart individual Deco units in any order. If you plan to do full Deco mesh restart on a regular basis, as it were already recommended just set...

@zcx This TP-Link FAQ article may help, too: How many Deco units can I add to my Deco mesh network? If you run Deco mesh in AP mode, my recommendation would be not to connect all Satellite Deco...

@HSSG Do you have WiFi still enabled on modem? What you describe may be happening if some of devices connect to modem WiFi and some - to Deco WiFi.

@Oliblo 15m is close to maximum recommended distance between Deco units, and that when there is open space between them. If there are walls the recommended maximum distance will be less. You can try...