Had this issue resolve by getting a whole new iphone. No matter what i did to the phone, it only worked for a while then got sim not inserted error. this happend about 7 eight times since i got the phone. i called apple and they had me re inserted sim card, then had it replaced, then reseted network settings, then factory reseted the phone and finally apple decided it was none of the above and gave me a new phone. So theres no magical fix here or trouble shooting to do other then take it to apple and swap it out. no matter what i did the phone worked for a while then got sim not inserted.