No/Slow Internet with Unbound & Adguard

[wsp3]

Hello together

I have a problem and don't know what it is.
I have set up Opnsense with Adguard and Unbound and this works for 2-3 days without any problems. But then suddenly I have no or very slow page loading (but when the speed test loads it is the normal speed 500mbit/s). If I connect my computer directly to the router again, there is no problem. I also don't know where I could look to check what the problem is but I think it is DNS?

I have implemented my setup according to these instructions:
https://windgate.net/setup-adguard-home-opnsense-adblocker/

Here are all the settings where I have configured something:
https://imgur.com/a/AxGNcTO

My Internet is set up as follows (unfortunately I can't configure much on the ISP router and I have to use it)
ISP (ipv6 only) -> Router (from ISP) -> OPNsense -> UnmanagedSwitch -> Clients

It is also not fixed when I deactivate Adguard and set Unbound to port 53 again. I have to factory-reset the firewall.
Without Adguard everything works fine.

Does anyone have a solution?

Thank you very much

OPNsense: v25.1
Adguard: v0.107.63

P.S I just started OPNsense a few days ago for the screenshots, right now i am directly connected to the ISP-Router

[9axqe]

I would start by checking that DNS is actually having an issue. While the issue is happening, do DNS lookups on your computer, use completely new domains or flush your local DNS to be sure the computer is not working off its DNS cache.

What are the lookup times?

The other thing you could check when the issue is happening, is memory and CPU usage of the opnsense machine, maybe bandwidth utilisation on the LAN interface too.

I am running AdGuardHome with Unbound, exactly this setup, and it works just fine for me. But I did not use these instructions, so I might have some difference, I didn't check everything in detail. One deviation of my setup is, I am not using port 5353 for Unbound but 53530. I did this because 5353 is used for mDNS and I thought, I'd rather use a port which is not commonly used for anything.