Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/EFR32BG22C224F512GM32/SMU_S/ESAUMRB45#0x0
Specify the boundary between regions 4 and 5.
Moveable Region Boundary 4-5
https://github.com/cmsis-svd/cmsis-svd-data