I did. Both of them connect to the same router.
Well...perhaps I didn't explain clearly in my poor English.
But....
I just tried something else, and I found that the reason why they are not on the same network might be that they have differentdefault gateway.
My router is xxx.xxx.200.x, but sometimes the APP sets my pc's to xxx.xxx.204.xx or something else.
I can't control it:
If I changenetwork adapter options manually, my app account will log outimmediately[so I won't be able to access the Internet].
But I found that I can refresh my gateway by logging in/out until it turns into 200 so my Quest can connect.
[which means that they are now on real LAN]
I'll try it more times to find out if it's a solution.
It's a bad network environment issue in work place, I'm just holding a little hope that someone can help.
Anyway, thanks for you answer.