Maybe you can clear browsing data, hope this help

Nyltak wrote Model : Hardware Version : Firmware Version : ISP : So a firmware update has come out for my router, and every damn website I try to visit this stupid popup telling me to update my...

I hope this can help you.

It seems that your Archer C5 is faulty. You would better contact tplink support.

Have you checked the connection speed? If your connection speed is 1Gbps, you would better contact TPlink support.

TP-Admin wrote Hi All, Following initial research and investigation, our Engineering Team is confident that they've determined one of the key origins of the issue. From what we have gathered so far,...