Changing SOA Serial under AZURE DNS

I host my DNS under Azure.  I'm making a transition to Azure slowly.  When I check my azure SOA I get a serial of 44.  How do I change this?

I have tried:

PS C:\WINDOWS\system32> $rs = get-azurermdnsrecordset -name "@" -recordtype SOA -Zone $zone
PS C:\WINDOWS\system32> $rs.records[0].SerialNumber = "2015122300"
PS C:\WINDOWS\system32> set-azurermdnsrecordset -recordset $rs

This does not change the serial.

I can't seem to convince azure CLI to work anywhere  I keep getting infinite loop on login.