Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Renesas Electronics/R7FA4M1AB/RTC/RCR4#0x0
RCKSEL=0
RTC Control Register 4
Count Source Select
0 (0): Sub-clock oscillator is selected.
1 (1): LOCO clock oscillator is selected.
These bits are read as 0000000. The write value should be 0000000.
https://github.com/cmsis-svd/cmsis-svd-data