SDMMC not working on STM32H7

[Archon]

Good day

I have created a board that contains a SD card, which works great with L4, F4 and F7 microcontrollers. This board allows me to swap out a F7 uController for a H7 uController since pinout is the same.

However, no matter what I do, I cannot get the SD card to mount/open or generally just work. I have tried using a nucleo dev board with a SD card breakout. I have tried different SD cards, and naturally I have tried various configurations using CubeMx. 

Can anyone tell me where I have gone wrong and how to get the SD card to work in 4bit wide bus? It should not take this much effort to get the SD card to work. 

Please see attached my .ioc file and the content of my main below.

[FBL]

Hi @Archon 

Initialize in 1-bit mode then switch to 4-bit mode through a later call