System Reset doesn't work as expected

[rbenv.3]

Hi,

I need to reset all, then tried to call "HAL_NVIC_SystemReset();", expecting a total reset (both nucleos CM4 and CM0), but it seems BLE app doesn't reset and goes to an undefined state, accepting connections, but doesn't accepting access to characteristics. 

Tried to write some data to RTC backup registers, but the BLE erases it during power-on.

I didn't find what backup data registers I can use in my own application without interfering with BLE data.

 

[rbenv.3]

Also noted flags IWDGRSTF and PINRSTF, but are expected : SFTRSTF and PINRSTF.