Hi,
I have the same problem. Coturn on Azure works as STUN but for TURN on some browsers only a relay is returned that is total BS, because the relay address is the Coturns 10. private network at Azure. Annoyingly we have static public IP for the linux at Azure but still this is what the server knows:
$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:0d:3a:b6:1f:d5
inet addr:10.0.0.4 Bcast:10.0.0.255 Mask:255.255.255.0
inet6 addr: fe80::20d:3aff:feb6:1fd5/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:12132507 errors:0 dropped:0 overruns:0 frame:0
TX packets:13463293 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:12320564299 (12.3 GB) TX bytes:2435424669 (2.4 GB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:168 errors:0 dropped:0 overruns:0 frame:0
TX packets:168 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1
RX bytes:12232 (12.2 KB) TX bytes:12232 (12.2 KB)