Graphene OS on Pixel 6 Pro, 7 and 7 Pro. Behavior identical on all 3 phones. After dialing a certain financial institution (any of 3 numbers) I receive a spam call immediately, even before my call is answered. The inbound calls originate from all over the US. Started beginning of March. Does not happen dialing any other numbers. Does not happen if I put one of the sims in an S10+. My phones are pretty simple, no other dialers or voice apps.
The phones are ATT through Patriot mobile. Tested with just cell network and then just wifi calling, same thing happening both scenarios. I had a long discussion with Patriot today and they don't even see the piggyback calls in their call logs. Any thoughts? TIA