Two extensions 721 and 722 are members of "Ring All" ring group 951. Two virtual extensions 90001 and 90002 in a Patton PSTN gateway are set to connect inbound calls to ring group 951. Custom parameter ALLOWUSEBUSYOPTFORGROUP is set to 1, because the phones need to ring even if the the secretary is already on a call. Last night I upgraded from 3CX 12.5 to 14. In the process I also upgrade the firmware on all of our Yealink T46G phones to the included 22.214.171.124 firmware. Now if both virtual extensions 90001 and 90002 have an inbound call and the secretary on xt 721 answers a call, extension 722 also answers the same call on speakerphone, even if no-one is sitting at the desk for xt 722. It is essentially a 3-way call between the inbound caller, xt 721, and xt 722. What would cause 722 to answer the call? 722 answers the call at the exact same time that 721 does. Both phones stop ringing at that point, even though there is still another inbound caller on the other line, and ALLOWUSEBUSYOPTFORGROUP is set to 1. I don't believe we had this problem until after upgrading to 3CX v 14 and upgrading the firmware on the T46G phones.