Thank you for getting back to me.
I have checked the speed while connected by ethernet and it is similar, 13 mbps. The connection problem is on all devices, several times a day all devices connected to the router (normally 4 maximum) will say they have lost connection from the internet, then reconnect after about 10 minutes.
The lights on the front of the box have been many combinations. Currently the bottom light is white and solid, but this has been solid green or flashing green occasionally over the past few weeks. The lights above it are currently all coming on every 5 seconds roughly, sometimes flashing, sometimes solid, sometimes only the middle of the three is flashing while the other are solid. This morning at times just the wifi light was solid green with the solid white light on at the bottom. Apologies if this is confusing, but there hasn't been much of a pattern.
Thanks again