Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/EFR32MG24A010F1536GM40/SEMAILBOX_S_HOST/RX_HEADER#0x0
A read access to this register will be mapped to the RX FIFO (only for the header).
RXHEADER
https://github.com/cmsis-svd/cmsis-svd-data