Unable to access GUI

I have changed the settings of the GUI to use a different port (like 80) and it worked perfectly.
Then I set the port back to 443 and now I cannot access the GUI at all.

All services are running properly, everything is functional as NAS, but I need to get the GUI back…

Rebooted - didnt help,
/opt/rockstor/bin/initrock - all good, but didnt help.

Any idea how to troubleshoot what is happening to the GUI?
Is there a setting that may have it disabled?

Thanks a lot,
Luigi