My main P9 is frequently losing internet connection.  This has happened previously and I tried resetting it which has helped for a month or so (either that, or it just turning it off and on fixed it) but it's randomly started doing it again, even though nothing has been changed - using same version of firmware, P9 plugged into the same plug, etc. I've tried rebooting and resetting it using the button in the base, but it's still dropping the connection several times an hour.

I have internet at my BT Router, so the problem is definitely with the P9.

I know the TPLink strap line is Reliably Smart, but this thing couldn't be any less reliable tbh.  Unreliable Shite would be more appropriate