I've had the router for 3 years without any problems. However, in the past few days I've had an issue where any device attempting to connect to the 2GHz Wi-Fi connection cannot get an internet connection as it's failed to obtain an IP address. This doesn't affect the 5GHz connection nor have I had any issues with my PC over LAN. Both the 2Ghz and 5GHz channels are set to Auto. There are ~3 devices (usually 1) connected to the 5GHz and 7 devices on the 2GHz connection.

I am running the latest firmware which is 0.3.0 0.9.1 v006c.0 Build 170809 Rel.42095n. According to the site the latest is Archer_VR2800V1_0.3.0_0.9.1_up_boot(170809)_2017-08-09_11.47.53.

Attempted fixes

1) Reboot the router. However, this only works temporarily. It would only occur once a day now it's once every 2 hours or so.

2) Factory reset

There is another router downstairs on a separate line but never had this issue before. The property is end of terrace so there's only 1 attached neighbour and there should be minimal Wi-Fi/signal interference.  It has been suggested that I should change the 2GHz channel manually as it's on Auto.. Would that make a difference with issuing IPs?

Thanks.