Hunt Group Busy Policy *51 and *52

Recently the handset activation for Hunt Group Busy policy stopped working. 

What use to work:

#51 then the Hunt group extension, and #

Example #51 1234#

This will busy the Hunt  group and all calls will then go to the answering service.

The next morning, 

#52 1234# and it would turn off the busy indicator.

This stopped working for our main line, but it still works for a different hunt group.

I've tried moving the phone # and hunt group extension to a new hunt group, but the problem moves along with it.

Any insight as you how to get this working again?