Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/stm32/stm32wb/STM32WB35_CM4/QUADSPI/SR#0x0
status register
Transfer error flag
Transfer complete flag
FIFO threshold flag
Status match flag
Timeout flag
Busy
FIFO level
https://github.com/modm-io/cmsis-svd-stm32