Unfortunately watchOS 3.x can't connect to a Wi-Fi secured by WPA2-Enterprise.
I have experienced the same behavior in the past with watchOS 2.x as well.
This assumes:
- Your university's Wi-Fi is part of eduroam or uses a smiliar Wi-Fi login using your credentials (user name + password)
- Your university's Wi-Fi thus uses the WPA2-Enterprise security protocol
- You can connect to the Wi-Fi just fine with iOS devices like your iPhone
- You use an Apple Watch running watchOS 3.x
With iOS you can enter your credentials. They will get saved and can be transferred to watchOS. The certificate, however, cannot be provided from iOS to watchOS.
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Updated answer
divB has pointed out that the network uses a MAC address filter instead of the WPA2-Enterprise security protocol
Please make sure to provide your Apple Watch's MAC address to your university as well as your iPhone's MAC address.
You can find it on your iPhone:
Watch.app > General > About > Wi-Fi Address
airodump-ng
to do a packet capture of the raw data flying through the air and see what's happening - is the watch trying to authenticate with the network? Is it getting rejected by the access point? etc..