Q: I think there is a setting in my I pad forbed me from using hot spot , my sim works at diffrent I pad while it does not work with my I pad

Trying to use personal hot spot , it des not work . Using the same sim in a different device of the same type and operating system and generation it works correctly . It was working before in my I pad , why it is stopped , I wish to know , did I made a mistake ? what is it , did I changed the setting by mistake hindering the work of hotspot , advice me please

Yasser