Yes, you were correct it worked for a bit then boom down to crippling speeds, even took laptop next to router and still getting crippling speeds on 2.4ghz, must be major interference somewhere. Even at early hours you expect ppl to be in bed and its bad. Only works ok when powerline ethernet connected.

I've even managed to move router closer to our devices and see -49 RSSI and have the best signal compared to neighbours, but still no joy.

Yep, you're in the same situation we were when we lived in an apartment. Everything was fine until we got neighbors and then their 2.4ghz was stronger than our own in our own apartment!

The solution that ended up keeping the wife happy was to increase the speed on our plan and set the router to automatically manage its own channels so it will hop around like all the other routers were doing. Setting a static channel never worked for long.

Good luck!

I have also found 2.4ghz to be the culprit of low speed and this is in a relative large 4 bedroom house and being in the same room as the router. The signal around the house shows as fine (min of 4 out of 5 bars) so it's not bad signal.

I am not living there at the moment, so assumed it could be a problem with Virgin Media's network as whenever I went there I was lucky to get 60mb/sec through my iphone, and moving around house it could drop to 20mb/sec. As soon as I restarted the router it would get a higher speed (but still no where near max) so for along time I put it down to Virgin network and thought I'd deal with it when I move in.

Couple of days ago I was having issues with my CCTV so decided to finally have a look.

I turned off all the auto channel steering functionality as apparently this doesn't work well on VM. Tried changing 20/40mhz on 2.4ghz but as soon as the router restarted it would return to 20mhz. Tried changing channels between the usual 3 options 1,6,11 to no avail, might get a little more speed but not much above 80mb/sec.

So I separated out the 2.4ghz and 5ghz networks (would rather not have to do this) and problem solved. On 5ghz it's getting the full 200-220mb the connection supports. Even in the furthest away from the router still gives well over 100mb/sec. In fact, on 5ghz I could still get over 60mb/sec at the bottom of the garden or drive at either ends.