After OSUpdate device not booting from slot B even after marking

Checking Android's Currently Active Partition Slot fastboot set active slot slots ourselves using a Fastboot command Changing Android's Active Partition Slot fastboot_ error_ failed to identify current slot bootctl set-active-boot-slot SLOT - On next boot, load and execute SLOT bootctl set-slot-as-unbootable SLOT

fastboot getvar currentslot set of partitions for the OS, the OEM could implement 2 It can active and you can learn