I think I may have a fix for the issue. And now I'm wondering if a recent Unifi controller upgrade may have changed something (since the controller runs on my PC 24/7).

Anyway, in the controller I use static reservations for my devices and define my preferred DNS servers. I've had these settings for a couple years without issue... until the last couple of weeks... coincident with my issues. I had a number of updates.. from Win 10 updates, to a controller update to some Intel driver updates... so it is hard to track down what may have changed... if that indeed was the culprit.

Anyway.. on to what seems to have fixed my connectivity issue which showed itself by not finding shares unless I UNC'd them (\\IP address\filespec). I went into the adapter settings and changed the DNS server to the IP address of the router. See the attached image. I did this for the PC first and after a few minutes, it seemed to sort itself out and I could get into the laptop shares withing having to \\IP address into them.

I then went to the laptop and could not get into the PC shares without \\IP addressing into them (this seems to have been flaky... sometimes the PC name would work, and sometimes not). I then changed the IPV4 settings as described above and rebooted. After the reboot, I could get into the PC shares normally again without having to \\IP address them.

Unable to see Win 10 PCs in the network-ipv4-dns-servers.png

Thoughts anyone?