Forwarding GV# to a multi-POTS-line Asterisk system

This was working fine until recently, but now we cannot receive two calls at once.

GV# ‘G’ has two lines listed as phones ‘A’ and ‘B’, both are real POTS lines. These two lines are connected to a Digium AEX410 hardware card, in a system running Asterisk.

If we dial either ‘A’ or ‘B’ directly, and it is not in use, we get through to the IVR. If we dial ‘G’ it will dial both numbers and connect to one of them (the IVR picks up both, GV decides which one was first and connects the call to it). It used to be then that if someone else dialed ‘G’ it would dial both numbers again, and connect to the free line, no problem.

However, it appears now to not really be trying to dial after one call through GV is in progress via ‘G’. While diagnosing the issue with Digium, they watched the voltage levels on the AEX410 and saw that when dialing the first time there were voltage spikes for rings on both ‘A’ and ‘B’ lines, and once they got into the IVR you could see that one line dropped to idle voltage and the other continued to fluctuate (call in progress). After connecting one line and having someone dial ‘G’ again we didn’t see any voltage spikes - google wasn’t actually calling EITHER of the numbers after one call in progress through ‘G’.

Just in case we tried having AT&T put our numbers into a hunt group but this made no difference (other than that if we dialed ‘A’ and it was busy it would roll over to ‘B’ without any issues, but this didn’t solve the problem with GV)

Has Google changed how GV works, allowing only one call through at a time now, regardless of the number of phones connected in GV settings? Or is there some other issue at play? We can be fairly certain its not AT&T (POTS lines) / Digium (hardware) / Asterisk (software), since we can dial the POTS ‘A’ and ‘B’ #'s directly and everything works as expected.

From watching debug output in Asterisk, Asterisk does hang up the line properly, and if I dial the free line directly I get in, so if GV still allows multiple lines perhaps it things it’s still in use (in which case this is a problem on GV’s end for sure, but are they going to fix it ? )

Does anyone have any suggestions for troubleshooting this further?

If we didn’t use GV to handle voice mail when both lines are busy we could simply port our number and drop GV, but we rely on it. If this is a GV change and it is working as designed, are there any suggestions for a replacement front end service that could route incoming calls to ‘A’ and ‘B’ then roll over to ‘G’ for voicemail only if no answer?