I have v2.6.31 with push notification. My voip.ms line have a ring group to my home phone and my cell phone with zoiper. I have received a call today and i answered it with my home phone but my cell phone havent stopped ringing for minutes. I ended my call and the zoiper was still ringing. I had to tell zoiper to hang out the phone to make it stop.
At first, i thought it could be a bug with the ring group of voip.ms but i remember that i tried in the past to call me on my zoiper phone only (no ring group) just to see if it ring. I hangup the phone without answering on zoiper and i noticed the same problem. The phone continue to ring until and tell him to stop.