Resolved! USART3 bootloader pins not avaible in some packages, are they remapped?
STM32H5x3 / VQFN68 packageHas USART3 but AN2606 lists using PD8/PD9 that this package does not have.AN2606 has a lot of remapping mentions for specific packages. Is this one of them, or does USART3 and bootloader not work for this package?