Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Renesas Electronics/R7FA2A1AB/SYSTEM/SBYCR#0x0
SSBY=0
Standby Control Register
These bits are read as 000000000000000. The write value should be 000000000000000.
Software Standby
0 (0): Sleep Mode
1 (1): Software Standby Mode
https://github.com/cmsis-svd/cmsis-svd-data