Freezing

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Given that you've had three phones, all of which exhibit the same issue, would seem to point to one or more apps that aren't playing nice with the iOS, rather than a hardware issue. That begs the question, did you setup the 2nd phone from a backup of the 1st, and a backup of the 2nd, to setup the 3rd? If so, try erasing the phone and set it up as new, without restoring it from a backup, as suggested in the following article, however, try the other solutions first.

iPhone Frozen? Here’s What to Do If Your iPhone Keeps Freezing - iPhoneLife

You're welcome. Unfortunately, you'll have to redownload whatever free or purchased apps you had on your phone, one at a time, until you pinpoint which of them caused the issue. The most likely apps are Facebook, Messenger, Whatsapp, Snapchat etc.