dnsmasq randomly stopped handing out leases for a while

[thulle]

Just adding this to check if anyone else experience the same thing, don't think there's anything here to act upon since it magically healed itself.

I upgraded and simultaneously made the shift from ISC + unbound to dnsmasq.
Leases worked fine, then a day later the unifi AP loses connection with the controller.
I reboot the AP, and it doesn't seem to get a DHCP lease.

I couldn't see any issues with config, so I ran tcpdump on the interface, and it's just DHCP requests on repeat, never any reply.
I rebooted the firewall, same thing. Added a manual rule to allow any UDP traffic to port 67 just to make sure something wasn't up with auto rules, no change.
Restarted the service. Stopped and started the service. Nothing new.

Then I finally started dnsmasq in debug mode on the console, and suddenly the AP and then all wireless clients gets their leases.
I stop debug mode and start the service from the UI again, and then reboot the AP. Now it gets a lease without issue.
I checked the stats for the rules, no hit on the manually added rule.
It might've been the unifi AP doing something strange, but as I could see the incoming DHCP requests without reply it really seems like dnsmasq was acting strangely somehow.
Writing it down and filing under unexplainables personally.

Other than this 25.7 is working just fine so far.