iPhone 16 connectivity issues when using physical SIM in Italy

Hi,

I’m experiencing a connectivity issue with my iPhone 16 (model MYEE3QL/A) running iOS 26.2.1. The phone is unlocked and has modem firmware version 2.20.04.

The issue: While my phone works fine with physical SIM cards throughout Europe, it won’t connect to any network in Italy—it only displays “no service.” I’ve tested multiple Italian carriers as well as my home country SIM, and none work. However, these same SIM cards work perfectly in my older iPhone. Interestingly, when I switch to an eSIM, the phone connects without any problems.

Has anyone encountered this issue or have suggestions for troubleshooting?

Thanks,

Mark