Fixed the issue. As it turns out, it was a really dumb issue the whole time (as I expected). The only thing stopping me from connecting to both the remote node and the local node, was that CrowdRender defaulted to the port range 9669-9684 on the local and remote node, but for whatever weird reason, the default port range on my host machine was 9000-9015. Changing the starting port on the host to 9669 fixed the problem, and the plugin is now working and syncing correctly!

Well, I did click connect on the nodes, and it showed connecting on the bottom bar and didn't do anything else. The Linux node's SSD did end up failing the day after I replied, so maybe there was just something corrupted on that end?

Ok! So: 1. All the machines are running Blender 2.91.0 with Crowdrender v0.2.5, so there is no mismatch there. 2. When testing, I only had 1 instance of Blender running on both nodes and the client. 3. I had the names set as the device being used to render, but I'll change them to the hostname and see if that will fix the problem. (I was just manually typing the IP Address). 4. I did already have a different hostname for the linux one, on both copies of the node, but one of them kept changing itself. That bug isn't a huge deal though. So, as for everything else: The place where I saw synced was under the "Render Nodes" section. On the Windows node it said "this machine: synced" and the Linux node just said "this machine:" and nothing else after that. On my client, I couldn't view the status of the other nodes, and what I mean by that is, in the documentation it says that I should be seeing the node's name, then the node status, then 3 different buttons. All I see is the node name and the buttons, even though they are apparently connected, as when I hover over them they say "active node" and they show up as "ready to connect" My guess is that it's just refusing to connect to the nodes. I know I have the IP Addresses correct, as my modem control panel shows the IP Addresses, and I'm able to connect with other services, like FTP and Samba using those IP's. The only thing I can think of, which seems to be an issue with lots of network based software, is that either my modem, or the render nodes, are blocking the connection in some way.