Verizon calls to my Sprint phone get dropped

[13ducati13]

Started a couple days ago. Running Sprint Rom. I have my phone set to always Roam since I get awful service at my house.

Can't receive any calls from friends on Verizon. The phone will ring when I answer it I can hear myself echo and my friends can hear themselves echo. Seems other calls from landlines and other carriers come through fine.

Called Sprint and they are sending me a new phone not sure that is the issue though. Hard reset the phone yesterday back to factory still having the same issue.

Any ideas?