Iphone blocks calls randomly
My iphone just blocks calls randomly. This is what I have tried so far: I got a refurbished iphone 7 plus hoping that would take care of issue. nope didn't work. opened new icloud account, nope still same issue. limited access to contacts via other apps. nope. made sure blocked list was clear and restarted device. nope. updated phone. nope. None of that worked. After unblocking it only lasts for about a day before blocking again. The only thing in common between the old and new phone is the sim card?!?! Could this be it???? I just need a solution that will work! Anybody got a solution.
iPhone 7 Plus, iOS 15