Specialized firmware designed for repairing baseband/unknown IMEI or fixing "Emergency Calls Only" after repair is often found on tech forums (e.g., this YouTube video guide ).
: Standard manual patches often fail after a factory reset or a restart. Auto Patch firmware aims to make the network fix persistent within the system partition. J730f U8 Auto Patch Firmware
Several tools and methods can be used to auto patch firmware on Samsung devices, including: J730f U8 Auto Patch Firmware