Flash Loader Demo could not work with the STM32ML4xx

When I used the Flash Loader Demo to connect with the STM32L412, it could not connect successfully. I checked the AN2606, it said the MCU will reply two ack (0x79) this is different than others. I guess this should be the problem to block the connection. (if I used any other terminal tool, it could connect successfully. it said the bootloader mode is entered.)

When I used the Flash Loader Demo to connect with STM32L433, it could connect successfully, but it could not select any device in the target selection. So it could not do next such as program and so on. The screenshot is attached.