Verizon unlocked phone moved to AT&T Network (adding plus sign to incoming calls!)
I recently left Verizon and converted to the AT&T network. I brought four Verizon unlocked Samsung phones with me. The two Samsung Galaxy S9 Plus phones are working fine, but both of the Samsung Galaxy S7 phones have a problem with incoming calls. Those two phones (or the network, or the SIM card) adds a plus sign (+) in front of the incoming phone number....., (NOT "+1", just the "+"). Then when I try to call that number from by "Recent" list, the number has the plus sign, followed by an area code and number (+903 xxx-xxxx). That is an incorrectly formatted phone number and the call does not go through properly..., in fact it gets routed to +1 617 963 yyyy, and a message shows up briefly at the bottom of the screen that says "Number changed by SIM".
I have tried turning off Assisted Dialing. No change. I have seen others with this problem who used an Android app called Prefixer to successfully strip the + sign from incoming calls. Unfortunately, Prefixer is no longer available from the Google Play Store. I am at my wits end! Does anyone have a reliable source for Prefixer...., or another solution that I can try???? Does AT&T have a remedy for this issue??? Thanks in advance for any help you can offer!