Upload speed dropped to 1mb/s

[#1]

I have had this problem for a while. My upload speed was around 10mb/s but has dropped to under 1. I previously raised a fault and was given a second tg582n router. Changing the router fixed the upload speed but only for a limited time and it drops back down to under 1mb/s again. Whenever I switch the routers over the upload speed is temporarily fixed, but every time it drops back down. The download speed remains perfectly fine however.

[#2]

Your upload sync speed has dropped to 1.3mbps so I'm not sure why you were sent a new router.
Have you tried rebooting the Openreach modem?

[#3]

Yes I've tried rebooting both. It only seems to fix temporarily when I switch the routers around.

[#4]

The sync speed relates to the Openreach modem so it shouldn't make any difference.
I'd recommend raising a fault here
https://faults.plus.net