Unplug your router and Internet modem/gateway from power. Leave them disconnected from power for at least 5 minutes to clear their caches. After 5 minutes reconnect power and once the network is back up try the game again on Ethernet.
If it still won't connect try connecting to a different port on the router. If that doesn't help try using a different ethernet cable.
Not much else can be done if you have no control over what you're connecting to. My guess is the University wifi routes traffic via some different hardware than the Ethernet and something on the Ethernet side is interfering with the communication.