I've got a TPLink AX1800 router - installed Aug 21 - that's been running fine up until last weekend.  On the Saturday the internet speed on my wifi-connected laptop went to almost zero - speed tests showed between 0.1 and 0.01Mpbs.  All other devices (26) on the router were fine and unchanged. The wifi device on my laptop appeared on and could hotspot to my phone ok.

A reboot of the router seemed to fix it for 24-36 hours, then it happened again.  The connection appears to be throttled down to almost nothing.

• I can't see anything in the system logs,
• don't have QoS turned on,
• laptop restart doesn't change the speed,
• setting a (different) permanent IP via DHCP doesn't fix it,
• connecting to the guest wifi network doesn't fix it.
• No recent driver updates to that wifi device
• up-to-date on windows patches, Win10  

Rebooting the router again got it back to normal for another 24 hours.

I can't even find anything in the menus to manually throttle a device, except perhaps QoS. I tried turning on QoS, and adding ust that device as high priority, but didn't appear to change the speed.

Any ideas?

Thanks.