STM32F103C8Txxx custom board, glitches after few seconds

[MDebo.1]

Hello everybody,

I made for school a custom stm32f103C8Txxx board.

Programming with a ST-Link V2 work without a problem.

To test the pcb, there are 2 led's (pin pc13 en pa10), they both illuminate every 500ms (easy code to test functionality).

The code wil run, for a few seconds and then glitches and does not respond... even after reset, it will glitch instantly.

If I dissconnect power for a minute, it will work again, but only for a few seconds and then glitches again.

Any ideas what it could be?

I added the schematic for everyone to see (don't mind the usb-c stuff, those components are not place on the pcb)

Edit 1:

Boot 0 and Boot 1 are determined with jumpers. Some parts of the schematic are based on the blue pill.

[MDebo.1]

my code is made in arduino, converted in bin and then uploaded by STM32 ST-LINK Utility.

[MDebo.1]

But I assume pc13 would still work for just blinking a led? it's the same on a blue pill? Didn't really look into that.

[TDK]

The reference manual says PC13-15 should not be used to drive loads like LEDs, but I’ve done so (before I knew better) and never had issues. YMMV.