3CX Phone system failed to work behind the Beta (where 17.1mr3 ET AL Previous worked fine)

Our 3cx phone system could not negiciate port 5060.  The rules are fine and working on 17.1 MR 3.  Updating to the beta had numberous issues.

SIP failures and ports not working. 

DNS failures (related to phone system only)

Rolled back (as you do) no issues with 17.1.MR3.


Still testing on my Sophos SG135W.