So this apartment building has a thing where all the units come wired for internet access and you just have to pay the ISP but it basically "just works." You can plug ethernet into the wall or you can use the wi-fi access point that they supply. Except the signal strength on the access point is bad, and the only way I could get it to be usable was to hook up a Google Wifi via wired ethernet and have it create its own wi-fi network and connect everything to that.
So that's fine, but we also had our old wi-fi router from our previous apartment, and we brought that and connected it to the network too (because it has a NAS connected to it and we wouldn't be able to connect that to the network via the Google Wifi or something. I dunno, the NAS thing is my partner's and I've never really been sure how it's supposed to work). I think that router is also creating its own wi-fi network, but nothing is using it.
Most of our devices connect to the Google Wifi's network and it works fine, but I have one machine that connects directly to the router via wired ethernet. It can see the NAS, but the wi-fi devices can't, but that's kind of irrelevant. What I want to do is transfer a bunch of data from that machine to one that's on wifi. This seems to be impossible, I guess because the wired LAN is considered one network and the wi-fi is a separate one. I tried making them both use the same subnet, but that didn't seem to work. I just want all of this crap to be on the same network!