Checksum bug in BlueNRG-2 Bootloader

Is there a checksum bug in the BlueNRG-2 Bootloader for the "number of bytes to read" field for the Read Memory Command? Checksums seem to computed properly for all other data transfers except for this one. Length always seems to be 0xFF and checksum should be the same but is always 0. What is the correct checksum computation logic for this field?