Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32u5/STM32U599/GFXMMU/GFXMMU_LUT37H#0x0
GFXMMU LUT entry 37 high
Line offset Line offset of line number x (i.e. offset of block 0 of line x)
https://github.com/modm-io/cmsis-svd-stm32