Automatic DNS doesnt work for Wireguard after stopping Adguard Home

(Tested on Version: 4.0.0 release2)
I am using Wireguard Client (Proton VPN).
I then started Adguard home using Dns ovet TLS (NextDNS). All is working fine but if I stop Adguard Home, DNS from Wireguard doesn’t work anymore and I can’t surf (DNS is set to Automatic in DNS tab and it’s showing “DNS from Wireguard”).
If I enable DNS over TLS (using stubby), all is working again but if I try to set DNS on Automatic, I can’t resolve any DNS.
Nothing useful on system log…

We are trying to reproduce this issue.

Do you mean you have input “tls://” in AdGuard Home’s “DNS settings” page?
Did you update AdGuard Home version manually?

Yeah, I used “tls://” and all was working flawlessly.
The problem arised when I stopped Adguard Home from UI.
Wireguard DNS were not working anymore after that. I can’t surf most websites. For example, I can surf, I can do a Google search, but most websites won’t open (Chrome is giving me a DNS probe started message).
Also, this is dnsleak result:

Re-starting Adguard home fix the problem (or manually changing DNS in DNS tab).
Anyway there’s no way tu use Wireguard client again without Adguard Home or without manually changing DNS, I think I have to reset the router and retry from scratch to reproduce the iussue.
Wireguard configuration was working without problem until I started and then stopped Adguard Home.

Ok, trying to reproduce the problem, I found the culprit.
This was happening because on WAN interface “Use DNS servers advertised by peer” was UNCHECKED.
Strange thing is that I didnt unchecked it manually… so I really don’t know what happened there…

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Ok, today this happened to me again when I was testing some Wireguard client servers.
I switched from a couple of servers, then after a little while I stopped Adguard Home, and the problem came back. I couldn’t surf or resolve any DNS. This time “Use DNS servers advertised by peer” was CHECKED.
Again, nothing useful on system log. This happened after I completely reset the firmware and reconfigured the router. Defenitely there’s something wrong…

@dengxinfa can you check if this is a bug?

Ok, after trying a lot, seems that’s not related to Adguard home.
How to reproduce this DNS problem:
Reset firmware, setup PPPOE connection, check “Override DNS Settings for All Clients”, Start Wireguard Client (Proton VPN), set-up VPN policy (MAC ADDRESS) to exclude at least 1 device from VPN.
Then reboot, DNS resolution doesn’t work everytime for me. To make it work again, I must stop Wireguard client or, if Adguard home is activated, I must stop it (that’s why I thought it was Adguard home related).
But sometimes just switching WG server makes the problem arise again.

This seems a very complicated operation. I asked developer to investigate.

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