Taoman,
If my wife is not going to be in the office, she forwards her office phone, via her office phone system, to the CC # which rings in another location were she will be, "location#1", through the OBi in that location. The OBi there is set up with this CC # for incoming calls. If she does not answer, after 11 rings, the work voice message plays the same whether her work # is forwarded or is NOT forwarded. So when she forwards her work number to the CC #, and she does not answer, her regular work voice message will play after so many rings. This works fine.
If someone calls her work number they get this message after so many calls. If I call her work number I also will get this message after so many calls. This all works fine.
It is only if I call her work number from "location #2", through another OBi using GV for out going calls that I get this message, after 11 rings.
As you suggested, I called her work number thru Hangouts at "location#2", and all works, we hear her message. It appears to be an OBi issue, maybe timing out after 11 rings.
I hope I have made this clear.