PC can't make socket connections after running game in editor

When I run my game within the editor, it works fine but my PC can't make any socket connections at all after I start it. As in, I can run servers that listen on ports (and other computers on the network can access them), but all "outgoing" connections, whether to my own computer or to anyone else's, is broken. It is fixed from when I restart the computer to when I accidentally hit the play button again.

This is a school computer so it's probably due to some interaction with a daemon that's running on there.

Can any Unity veteran tell me what kind of weird stuff is going on under the hood that might cause it to break?

edit: To expand on this a little, it looks like it happens whenever the debugger is connected — not just in the editor but also built products — and only when unity is running at the same time as my game.