Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32n6/STM32N645/LTDC/LTDC_L1CFBLNR#0x0
LTDC layerx color frame buffer line number register
frame buffer line number
https://github.com/modm-io/cmsis-svd-stm32