In CubeMX 6.6.0 and also 6.6.1 there is a bug, in my opinion.Most likely this came with the latest Fix 34380 (Alternate functions in PA0, PA1, PC2 and PC3 are not available in PA0_C, PA1_C, PC2_C and PC3_C GPIOs)Selecting STM32H750XBH6 (TFBGA 240+25)...