Hello,The problem came from specific backup registers that needed to be reset.You can find below the SW excerpt related to the needed action:HAL_Init(); HAL_DBGMCU_EnableDBGStandbyMode();__HAL_RCC_BACKUPRESET_FORCE();__HAL_RCC_BACKUPRESET_RELEASE();T...

Hello Jan,Thanks for your feedback.I could connect to the target via ST Link:11:09:56 : Connected via SWD.11:09:56 : SWD Frequency = 4,0 MHz.11:09:56 : Connection mode : Connect Under Reset.11:09:56 : Debug in Low Power mode enabledPF