Local DNS server being "forgotten"

[Yeraze]

I have a local running DNS server, just to provide hostnames for my internal LAN, and connected to AdGuard. It works great.

However, I've noticed that if I down the server for any length of time (even just a few seconds), so that AdGuard tries to resolve something and can't reach it, then it seems to just totally forget it exists and then nothing on my network can resolve names until I restart AdGuard.

I've verified this with dig @<adguard1> <internal name> which returns nothing, but dig @<my server> -p 5353 <internal name> which returns the actual IP. Then I restart the AdGuard home instance, and it's back to normal.

Is there a setting to make this more persistent?

(Running 2 adguard-home instances on two separate pi's, with adguard-sync)

[Yeraze]

I was able to resolve this by raising my timeout from 2s to 30s (long enough to account for the server restart with a healthy margin).