Random "Server not found" issues with DoT enabled on RT-AX86U Pro

[wiremonkey]

I've followed all ASUS and DNS-provider instructions to enable DoT for either (and both) Quad9 and Cloudflare on the router and in all cases I've suddenly started getting random "Server not found" errors on all connected devices in daily use. As soon as I disable DoT, this issue disappears.

Has anyone else seen such a thing? The worst part is DoT worked perfectly fine on this router with no such issues for many months (and an RT-AC86U before it). It seems like it started around 3-4 weeks ago and nothing had been changed.

 

[dave14305]

Similar thread recently. Could be the providers.

DNS-over-TLS taking too long RT-AC86U

Many times during the day DNS will take too long, and I get a Server Not Found error in the browser, even for sites I'm accessing frequently. It's not just the browser, I'll get it in other apps like git-bash occasionally. I never had this problem before switching to DNS-over-TLS. Attached is...

www.snbforums.com