Cannot get two computers to see each other on home network

I'm trying to use a printer on one computer (USB connection) on another. This was working just fine until last week, when suddenly it stopped.

The two computers are part of the same powerline network. Internet access is through a cable modem/router on a third powerline adapter.

They used to be able to see each other -- I added the printer as a network printer by using the "Browse" option. I'm not using Homegroups but instead just had it as password authentication.

For whatever reason, the computer with the printer now just doesn't show up to the other one, and vice versa. I've checked that network discovery is on, that the LLT protocols are on, and they are. They were before, nothing has changed.

Strangely, when I have windows generate a "Full Network Map" for each computer, they are different. One PC shows Computer ==> Gateway ==> Internet, and the other shows Computer ==> Switch ==> Dlink router ==> Internet. Even more weird is that I don't own any Dlink hardware, but it could just be seeing a manufacter's part inside another branded device.

Does anyone have any suggestions? Where can I start to even troubleshoot this? Thank you in advance for any help you can offer

Did something you know of actually change a week ago, when your home network's configuration apparently changed? Did you replace any hardware? Visits from cable company? Anything?

Can you please do IPCONFIG in a command-prompt on both machines. Please state what each machine shows in its "local area connection" info. I'm looking for IP address details on its IPv4 address, default gateway, DNS router.

Also, you've provided no info in your specs, and you have two machines to describe. So please provide specifics for each machine:

wired vs wireless connection from PC to router? Please list all devices involved, and if wired what they connect from/to.

brand/model of router? brand/model of your powerline adapters. Do you have an actual true "switch" (which is actually a device type), or only a primary router/modem, or what else is involved in your home network. Can you verbally describe your assumed connection path from each computer to the primary router (and then to the modem, unless you have an all-in-one box from your ISP that is both modem as well as router).

are both machines in the same "workgroup"? Right-click on COMPUTER, select Properties, and look down in the "computer name, domain, and workgroup settings" section. What is the "workgroup"?

what are the "attached devices" (presumably and hopefully showing both of your PCs) shown in your router's GUI? Screenshot from a browser window where you've connected to the router (e.g. 192.168.1.1, or whatever the "default gateway" address as shown by IPCONFIG).

A printer USB-connected and hosted by one machine on the network can be shared with other PC's on the network as long as it is set as "shared" in Printer Properties -> Sharing tab, from Start -> Devices and Printers. If that part looks good from the hosting machine, then it's obviously an issue with the two computers not being able to see each other on the network.

We'll get to the bottom of it, but the above info is needed first to get a clear picture of your home setup.

Thanks I will get back to you with this info.

I got sidetracked by Xmas and a new job. Anyway, the problem fixed itself. I am guessing it was something to do with the powerline network, because while I don't recall a specific incident starting the issue, we had a power outage last week, and I had to reset the network (unplug all adapters, add them back one by one) and now I can see every computer and printer again. No idea why it went haywire in the first place.