25.7.11_2 - New devices don't seem to receive DNS request responses

[longshot338]

I have been running OpnSense for several years, and it has been rock-solid.  Recently, however, I have noticed that new devices being added to the network (behind OpnSense) are not getting to the Internet for some reason.  All of my legacy devices work fine, however.

I opened the firewall live log, and I filtered on my host(s) IP address(es), and all I see are DNS requests.  I see the request being allowed through the LAN interface, and then I see a NAT hit for the traffic going out the WAN interface.  That's it!  I don't ever see anything going back to the host(s); nor do I see any attempt to establish a connection to any Internet address.

Does anyone have any idea why this would only be happening with new devices, or more importantly, does anyone have any suggestions on how to resolve it?

Thanks for any assistance that you can provide.