I have two SIM cards, which are inserted into two mobile phones. Why can't one party send a message to the other?

This is a cell phone problem. I'll tell you to restart your phone. The old mobile phone has been used for a long time, so it is normal not to receive it. If you have time to clean up your phone's junk memory storage space, your phone will respond better. Take it easy. My mobile phone gets stuck every day. Someone called me face to face, but my phone didn't ring. I can make a phone call. Strange, I can't get the verification code in front of the dealer, and the dealer won't restart my mobile phone. Just like you, I thought I was stuck the last time I checked.