@ToniK2000 Based on a quick Google search cat 6 STP give good speeds(1000) even up to a 100 meters, so I do not think it is the length that is the issue. Perhaps the RJ45 connector is not for high...

@Bogdanus I suspect this is a ISP (Internet Service Provider)configuration issue so most likely a reboot will not fix it. You mention a previous router tp-link wr841n does the old one work or is it...