cubeMX timebase tick prioirty

I am comparing the differences between the project/application for the STM32H7 FatFs example in FatFs_uSD_DMA_RTOS and a project created using CubeMX (w/STM32H7 V1.2.0) for the H743i_Eval board.  One of the differences is in the priority given to the tick interrupt.  In the example project it is set to 1 and in the CubeMX generated files it is set to 0.  I do not know if this is a significant reason as to why the project example works and the CubeMX generated version does not.  However, it think it interesting that CubeMX does not allow the setting of the Time Base priority as the NVIC configuration tab has the priority number preset to 0 and the values greyed out.