In that case, your router(s) are the most likely culprit, but just to eliminate the possibility of a setup issue on the OBis, I suggest removing one of them from your OBiTALK dashboard, then disconnect its Ethernet cable, dial ***8 on the attached phone, and then press 1 to factory reset the OBi. Then, power it off, reconnect the Ethernet cable, power it back on, add it back to the OBiTALK dashboard, and re-do the Google Voice account setup, on just one of your two Google Voice accounts. Test inbound calls. Does it work now? If so, add the other Google Voice account and re-test. Be careful when adding Google Voice accounts, to observe the gmail address in the pop-up window, to ensure you are linking to the correct account.