Been using three deco M5's in the house for a few months and all running okay.
 

Yesterday have a power cut to the house for some reason this put the virgin media modem back into router mode. I put it back to modem mode and TP Link adviced via Chat to set up the decos again due to issues. 
 

so with there help, I set up a new network, re-set the satellite Decos and reconnected them.

BUT... shortly after I had problems holding a connection. When I opened the app sometimes I could see the old network name, and then sometimes it would disappear, and the new network name would be there.
 

So yesterday I deleted the old network name on the app (top of App clicked on 3 ... on old network). But unfortunately it appeared to have deleted the new network as well, therefore I had to set it up for a third time again today but now having the same issues with the old network name reappearing and loosing connection.

Any advice appreciated, thank you!

(main deco is V3, kitchen V3, upstairs older M5. But I had no problems previously!)

EDIT: forgot I have a 4th Deco occasionally connected hardwired by Ethernet cable to a log cabin in the garden! 🤦🏽‍♀️ Problems happen when I connect it! So I need to set up this Deco again!