We have 1,000 boards with STM32L071CBT6, 20 of which cannot be connected to the MCU with Jlink, but can be connected to the MCU through USART.
Connect the USART and use the system Bootloader to burn the program to Flash normally, but the program cannot run after power on. We can guarantee that there is no problem with boot mode in all process, but we don't know what caused the failure.
