STM32G474 needs several power cycles to run code

[Amandeep_Dhaliwal]

I m working with STM32 MCU from last 3 years  i made many boards for STM MCU but i never face the problem which I'm facing now. In past i made boards for lower pin packages ( up to LQFP 64 ) mostly they have single power input pins this time i made a board for STM32G474 ( LQFP 128 )  it have several power input pins and i connected all them in design,

Now what issue I'm facing is that when i started firmware development i noticed that CPU do not run code automatically i need to disconnect it several time from power and then its run code and start consume power, in working condition circuit draw 0.09mA  from 12V rail and when its not start code its consume 0.03mA.

where is problem what I'm doing wrong here?

Is that something with reset pin? Because i did not pull it up externally. 

[gbm]

How could anyone help you without even seeing the schematic?

My 2 guesses:

- BOOT0 not connected to ground

- power supply problem - DC-DC not starting correctly

[Amandeep_Dhaliwal]

Yes BOOT0 pin is floating.

DC-DC stuff is fine 3.3V always present on MCU supply Caps.

[Amandeep_Dhaliwal]

Solved with pull down resistor.

I never used pull down on BOOT0 pins on previous boards that works fine with internal resistor that's why i go without external resistor on this board also next time i will keep it in notice.