Azure RDP failing.....

I and unable to RDP Azure VM on my corporate network using "DNS:Port" (like vmname.cloudapp.net:3389). It works fine on my home network, which means, endpoints are set correctly.

However, it was possible to RDP VM using Public IP but not anymore. With public IP, I was able to RDP VM on my corporate network, but not sure this has restricted recently?

Any way of to access a VM using Public IP rather DNS:Port format?

Thanks