Download / upload problems outside school network

From the link above i installed seafile server on one of our machines in my university.

At first i couldn’t reach the webserver from home because the ports were blocked by IT.
IT opened the ports 8000 and 8082 for the machine and made NAT for it to be accessed from outside of the school.

Now i can access my server, see all the files in client and in web but i can’t download or upload anything.

In school it works perfectly (haven’t done a stress test but it seems okay) but outside of the school i can only see files but nothing else.

Any help would be appreciated.