I've debugged this further and I think it's probably a kernel network driver issuer but I don't know how to categorize that appropriately in the bug-tracking system so some help in that regard would be appreciated.
`avahi-browse --all --terminate --ignore-local` returns no
results on the laptop that's not seeing any printers. It DOES
return results on the laptop that's seeing printers.
When I run wireshark and watch port 5353 on the laptop that doesn't see printers, I see a query going out on port 5353 when I run the avahi-browse command, but no responses coming back.
When I do that on the laptop that is seeing printers, I see both the query going out and the responses coming back.
Furthermore, when I run wireshark on the laptop that is seeing printers, and I run avahi-browse from the laptop that isn't, I see both the query come into the working laptop from the non-working one and the broadcast query responses sent by other machines on the network. It's just the non-working laptop that's not seeing them for some reason.
I've tried disabling my firewall (I use ufw) to no effect.
All this is happening with both kernel 6.6.13 and 6.5.0-5.
As noted before, I know this wasn't always broken; I was
definitely able to see printers and print to them in the past from
the laptop where I can't now.
As noted previously the two laptops involved here are configured essentially identically. However, they DO have different wifi controllers. The working laptop has:
[ 18.173347] iwlwifi 0000:a6:00.0: Detected Intel(R) Wi-Fi 6
AX210 160MHz, REV=0x420
The non-working laptop has:
[ 19.429101] iwlwifi 0000:02:00.0: Detected Intel(R) Dual Band
Wireless AC 8265, REV=0x230