Are you hosting a service that is not under your organizations official domain or something? It is common security practice to block newly created domains which may be why your domain is blacklisted if you only recently stood it up.
Sounds like your university is using a Palo Alto Next Gen Firewall which is intercepting DNS requests and responding with the sinkhole FQDN for anything they deem malicious or suspicious. You can try to override this with DNS over HTTPS but they may also be blocking that. Standard security stuff. You can also probably try to open an IT ticket and request that they whitelist the domain.
There’s gonna be a lot of culture shock from authoritarians throughout the fediverse it would seem. Some people don’t know what to do with a little freedom.