Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Renesas Electronics/R7FA4M1AB/CTSU/CTSUCHTRC4#0x0
CTSUCHAC4=0
CTSU Channel Transmit/Receive Control Register 4
CTSU Channel Transmit/Receive Control 4
0 (0): Reception
1 (1): Transmission
These bits are read as 0000. The write value should be 0000.
https://github.com/cmsis-svd/cmsis-svd-data