Hello. I have custom serial bootloader, which located in the beginning of user flash (sector0), and also user application, which burned by bootloader starting from sector 1 (slightly modified IAP example from ST). While in user app, I want to perform software reset to restart from my custom bootloader. The problem is, if I call HAL_NVIC_SystemReset(), my application just freeze. Also I tried IWDT reset with IWDG_Enable() with same result. Hardware reset from NRST pin working just fine. Also, if I call HAL_NVIC_SystemReset while in bootloader, reset working OK also. NRST pin connected to ground via 0.1 cap. No external pull-ups or anything.