2 identical spec Samsung S5's. One phone picks up all but one sim but that sim works on other phones

[Android Central Question]

Hi guys
My cousin and I have the same phone - Samsung Galaxy S5. He just came back from a trip overseas where he used the Galaxy S5 with a sim from his father

When he got back home, he put his original sim into his phone and the phone says Sim Card not detected. But when he put his sim into my phone it works perfectly. When I put my sim into his phone, my sim card is detected by his phone.

 

[methodman89]

Did he do anything to pair or lock his dads sim when he changed it? Do you have any security apps that detect sim removal?

 

[B. Diddy]

Welcome to Android Central! If there's a Reset Network Settings option in Settings>Mobile Networks, ​try that.

 

[ndb2018]

Did he do anything to pair or lock his dads sim when he changed it? Do you have any security apps that detect sim removal?

No i have no security apps and he didn't do anything to pair or lock the sim

 

[ndb2018]

Hi, I have tried that and still no luck