Is the OBi forwarding the calls, or is it GV? For example, if you unplug the OBi and call your GV number (from a phone not associated with your GV account), does the MJ ring? If so, it's not related to the OBi and you should seek help from Google or on GV forum.
Otherwise, log into the OBi directly (not the OBiTalk portal) and check whether you have any forwarding numbers set up, or have an InboundCallRoute that might be sending calls elsewhere. Also, check the OBi's Call History -- the call may be reaching your MJ via a roundabout path.