Unknown phone number

An app that I need is not recognizing a SIM/Phone number. ...But the problem is not the app: Before we go: I've visited other forums, but the answers are uneffective, completely unfit, or oriented to old androids. - If I go to Settings > About phone > Status > SIM Status, I get many *Unknowns*; - If I go to Settings > Connections > SIM management, the phone number shows *Unknown*; - I've tested on 5 different phones (see below). This problem happens on three of them, and works as supposed on the other two; - The phone receives and sends calls and messages; - I've resetted APN and stuff, as suggested on other sites; - There is no option to change my own number on any setting The SIM card is more than two years old. Below: - Does not work on a new Xiaomi, nor on a Galaxy A01 (gotta make work on this one). Calls and SMS work normally. - Used to work on a Galaxy S9. No one can remember when it stopped. - Works on two motorolas, one old, probably G3, and the other is a G6. Calls and SMS work normally. **Update:** it happens with another SIM. That SIM belongs to the G3 above. Both SIMs works well on the G3 and the G6, none of them has the number identified on the defective ones (Galaxies and Xiaomi).