[krypd0h]

I wouldn't be surprised if someone (your Uni) is mistakenly blocking some 169.x.x.x data since 169.254.0.0/16 is used for local IPs. Someone put the wrong subnet mask in a firewall rule or ACL someplace.

[vadiml]

This would prevent initial SYN To reach the server too.

[Hikikomori]

Not if you also match on established connections and outbound only.