I'm using the STM32G030C8 for one of my projects and i realize that in some cases the RTC stops when the power supply is up. While in VBAT supply the resonator works well and provide the correct date and time, but when i use the power supply the resonator immediately stops to work. The oscilation signal disappears in osciloscope. It looks like the microcontroller does not switch the power for LSE properly.
The crystal i'm using is the ECS 32.768 KHz 6 pF +/-10 ppm (https://br.mouser.com/ProductDetail/ECS/ECS-.327-6-34B-C-TR?qs=eP2BKZSCXI77Gsmdv1lxlw%3D%3D) with 10pF for load capacitors. The LSE Drive Level Capability is set to high. I even tested it with medium low and medium high and it doesn't make difference.
In 8 boards assembled, the problem ocurred in 2. We are having some low temperatures over here ( < 10°C) and the problems appear mostly in low temperatures, but even in our lowest temperatures it doesnt get even closer to the lowest operation temperature for the microcontroller or the crystal.
After some point the RTC begins to work properly both on VBAT and by power supply, but when i power up the board the next morning the same occurs and the time is freezed at the exact time i power up the board.
