That was always the case. From the samsung firmware version string U* usually indicates “bootloader version”, for example for A325NKSU4DWH3 its bootloader version 4
The same version number doesn’t really mean the same bootloader binary, this version is just for preventing downgrades. After installing a firmware with U4 you can’t rollback to a U3 firmware for example.
didn’t they also push that downgrade for older versions?
That was always the case. From the samsung firmware version string U* usually indicates “bootloader version”, for example for A325NKSU4DWH3 its bootloader version 4
The same version number doesn’t really mean the same bootloader binary, this version is just for preventing downgrades. After installing a firmware with U4 you can’t rollback to a U3 firmware for example.