Hi, I have been using iPhones 14Pro, 15Pro for the last couple of years for 5G SA research applications. As far as the iPhone14 Pro goes, even with the latest upgrade 18.2 beta 2 it works flawlessly, upon inserting the SIM CARD, I can activate VoLTE and then there is a toggle that enables 5G SA. The phone connects to the network using PLMN 001 01 and functions perfectly. iPhone 15 Pro is behaving completely different. Upon inserting the SIMCARD it also lets enabling the 5G SA functionality but the phone never searches for a cell. Even putting the phone into mobile field test, it never searches for NR even with the same SIM card working in the 14 PRO. This particular mobile phone did work in the first iOS versions and stopped working after upgrading to 18.1. Just a few days ago, I bought a 16 PRO to try it with our 5G SA networks, and it is behaving the exact same way as the iPhone 15 PRO. It never tries to attach to the 5G SA even with the same SIM card as the 14PRO. I would like to understand this difference in behaviour across all these devices and understand if this is a new implementation or a SW bug. In the case this is a new implementation, please point me towards novel documentation so I can understand what to change in the network configurations to have the communication back. Thanks.