Solved
STM32H7 VREFBUF wrong voltage in CubeMX GUI CubeIDE 1.6.1
CubeMX lets you choose 4 voltages.
Option/Value 0 should be 2.5V jnstead of the mentioned 2.048V
Option/Value 1 should be 2.048 instead ogf the mentioned 2.5V
Proof: When you select 2.5V it generates 2.048 on the VREF output.
