Archer AX50 LAN ports suddenly stuck at 100mbps
I've had my Archer AX50 router for almost a year now and was purchased due to Virgin Media's Modem Router not giving a steady connection. The addition of the Archer AX50 has made our connection so much more stable and massively improved the Wifi also but over the last week our wonderful 350mpbs internet speeds have been reduced to a meager 90mbps. I've factory reset both the Archer and the Virgin Media router and tested the VM router by itself before switching it back to Modem mode and this resulted in the full 380mbps connection speed we are used to. When I plugged the Archer back in to the VM router I managed to get around 280mpbs (A whole 100mbps less) and it dropped more and more as I added new devices to the network, which it hasn't done before. Now just to let you know that I've not added any new devices at all between when it was working fine and then not so fine.
A little background on our setup:
So I have a VM router connected to the Archer in Modem mode. Our connection is the VM 350+.
When then have all ports on the Archer filled with devices such as our TV, PS4, Philips HUE hub and then a 50m cat 6 Ethernet cable going upstairs to a small Netgear dumb Gb Switch.
The Netgear Gigabit switch then has my PC, my partners PC and our WD My Cloud NAS drive connected to it, all using Cat 6 cables.
Now the cable that was running from the VM router to the Archer was a Cat 5.e and saw this might cause an issue so I changed it to a Cat 6 but I'm still getting the same issues.
I've also checked on the AX50's settings and all the LAN ports are set to 100mpbs Full Duplex for some reason when everything bar the TV and the Philips Hue is running a Cat 6 cable and has the ability to receive 1gb at the other end.
Anyone got any ideas on this as it's driving me nuts that my download speeds have dropped so badly. Yet the upload speed remains solid!