Were your M9's purchased together? If so they should all be the same hardware version. But your satellite is running firmware made for V1 M9 Plus while your Main is running firmware for V2+. You can...

@delong91 I did, my mistake sorry. I thought the X60 was listed there It's a lot of expensive equipment to just dump though, I'd try to make it work. I actually am looking for an X60 myself so I do...

@SteveWex lol what do you mean dumped them? can't have been that bad surely. there was a firmware update somewhere to help with the decos showing offline if that's what the issue was

@Mattjtemp Sorry, just wondering, are you seeing better performance with the Decos in access point mode? I always assumed it was better to have them in Router mode. Wonder if I should consider...

have you tried turning off your modem for a while then turning it back on? https://community.tp-link.com/en/home/forum/topic/111130

@Mattjtemp just a suggestion. you could also log in at http://tplinkdeco.net/ and view the logs, not sure it will help