Odd error messages rt-ac86. advice appreciated

[eastavin]

Hi.

We have a Asus Rt-ac86 router with the latest stock firmware. It has been working fine until a few days ago when all browsers and devices going through the router see this sort of error message when trying to reach kijiji.

If we switch our windows 10 computers to use our LTE hotspot on our personal cellphones via a tether the problem vanishes. If we take our computers to a different building and use someone elses ISP everything works perfectly too. When we return to our normal place the problem is back.

Should I be suspecting the router as the cause? We contacted Kijiji and their support person said they are not the cause.

Advice appreciated.

 

[ColinTaylor]

Sounds like a problem with your ISP (or their peering with the CDN).

 

[Grisu]

Did you enalbe AiProtection?
Disable it (and reboot) and try again to verify if TrendMicro is the problem.
And you could try to change DNS-IP to a different one, e.g. google's 1.1.1.1 for testing.

 

[eastavin]

Thank you both. I will try all these.