I've had the Archer VR2800 for around nine months with no issues and considerable improvement over my ISP provided modem.

As of last Sunday I noticed a considerable drop in internet speed and stability, with various speed tests (including the modem's internal test) indicating download speeds of 3.2mb and upload of 1.4mb. 

After trying various solutions, I replaced the modem with my original sky hub.  Immediately download speeds returned to their original maximum of 14mb. 

I've since tried to switch back to the VR2800 at least twice, both times indicating a download speed of only 7mb.  There have been no changes or updates on my end and I'm at a loss as to the sudden and unexplained cause of such dramatic speed loss, particularly when the original hub shows it not to be a line fault.

Any assistance would be greatly appreciated.