I have the same problem with the sim card on tmobile with my galaxy note 4. The phone will tell me it can't detect the sim card and restart the phone, I'll have to do it two times to get it to see the card, probably getting a new sim card from your carrier will fix it, it's free if you're on the jump on the tmobile, I accidentally locked myself out of my sim card once by entering the pin wrong 3 times, they replaced it free.