Hi, I have a large very old house with thick walls and 3-phase electricity split by phase across the 3 floors. I have 3 P9 (bought as a pack) across the middle floor, and 2 M5 on the ground floor all in the same network.

When I initially got it set up and working, it was excellent - with very strong coverage and good speeds. It has become unusable during the last few weeks - and I don't think anything has been changed. Speedtest.net shows less than 1Mbps in both download and upload, while a simultaneous test on the plusnet wifi network shows 20Mbps in both directions (which i why I think I've narrowed it down to the Deco mesh has a problem).

The Master P9 is connected to my Plusnet router, and the 2 other P9's are on the same electric ring main in rooms above the corresponding M5 rooms. The Deco mesh is operating in AP mode as I could not get it working in router mode.

Looking at the forum, a firmware upgrade has been suggested - but I cannot connect to the web gui (http://tplinkdeco.net or the tplinkdeco.net:30000 suggestion), and the M5 refuses my IP address connection. Using the app on my iPhone to check for updates reports all up to date. and the version reported above.

Can you help me isolate and fix the problem?

Thanks,

Jon