The steady low line to the left of the graph is it using the “local network” from my computer (didn’t even know it had one) and it goes straight up when I interrupt it and tell to switch to the WiFi for download. And it keeps doing it so I have to switch the the WiFi manually every time. Why is that so and is there a way to “always use WiFi?”
Just turn off local transfers if you only want it to download from steam servers. As for why, to keep data usage down. No sense downloading a 100gb game when there is already a copy in my house or saturating the WAN for the rest of the house while it downloads. Lots of folks have usage caps as well.