I had a similar issue the day I upgraded to v2.3.2 back in July…. and I'm still convinced something changed, but that's another conversation.
As soon as I upgraded to v2.3.2, the DNS forwarder stopped resolving. I tried both the resolver and the forwarder to no avail. The fix for me was to deselect "ALL" from the interfaces section and manually selecting my "LAN" interface. As soon as that was done, DNS started resolving again and my issues went away.