I may not have all of the facts, but when I answer a GV incoming call on my OBi200, my Android Hangouts app phones continue to ring. This seem fairly repeatable..
I have Hangouts installed on a Wi-Fi only Samsung GS5 and a Lg Nexus 5X (Wi-Fi + cellular) both running Marshmallo.
Don't know if this is a GV or OBi problem.
Pete
Hi:
This is a known bug with Hangouts. Google is working on getting it fixed.