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I didn’t move any SIM card. Just turned it on, activated and that’s it.
same here. at first I was going to swap SIMs but noticed my new Max (AIUP) already had a SIM in it.....so I gave it a go and it booted right up and registered no problem.
 
I have the same simcard as my iphone 5 now , and had 6, 6s, 7, 8 and now xs and no issues ever
 
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