Getting HTTP 406 Not Acceptable on several sites

Hello,

Long time OpenWrt user, I've noticed I recently started getting "406 Not Acceptable" HTTP error when I visit several sites for example:

I have cable internet, if I connect directly to the cable modem from my laptop the issue goes away. It happens on any device as long as it on my network with OpenWrt as the router. e.g. mobile phone, 406 error with WAN, Ok with cellualr network.

I have a pretty much stock OpenWrt setup, the only additional packages are :

  • SQM-QoS,
  • nlbwmon
  • vnstat2

I believe something is mangling the HTTP packets hence resulting in this error. I tried turning of SQM-QoS (no reboot) but the same problem.

Could the bandwidth monitoring be causing this issue?

The only mangle firewall rule I see is set ingress and egress on WAN MTU and it shows as 1500 in the interfaces tab.

Any idea what the heck is going on?

Well, I changed my mac address and got a new IP and no more HTTP 406 errors...

came across this: https://www.reddit.com/r/PFSENSE/comments/l6bk9m/406_error_nginx_nothing_changed_home_network/

and it looks like I'm getting shadowbanned? Any way to monitor whats going out on my network?