Reset Loop after phone dies, persistent after 2x back end repairs

I have been having a constant issue with my iPhone 14, initially it started randomly resetting every 3-5 minutes. From there I had tried a software update, a system restore from my pc, a factory reset, and eventually after all that had failed I took it into the Apple store to get it checked out. They did a back end repair and the phone was fine until about 2 weeks later when it had died for the first time since, did a retry of the update, restore, and reset pattern from before and still nothing there. Back to the Apple store where once again they say it is needing a back end repair, after that another 2 weeks have passed and the phone has died for the first time since the repair for the second time. The same issue is back, and I am scheduled to go to the apple store again. Looking for some insight on why this is recurring even after the full back end repairs, and also if apple will just replace the phone after so many repairs.