I used Updater tool to update the firmware to modem 1.0.7 (github link given below).
During firmware updation, I noticed using LED status that flashing of firmware was completed, however following switch case to update to TX or MODEM was not executed. To identify the problem, I tried to reprogram the IC and check where the code got stuck. But on further execution of the code the BUSY pin was always high and no command could be executed after system reset. What could have been the issue here?