Setting the SINV register to invert UART I/O

Hello,

I am using RA2L1 MCU and I wanted to invert the UART I/O on P301 and P302 (SCI2), and for that I tried to set the SINV register using,

R_SCI2->SCMR_b.SINV=(uint8_t)1;

I am doing this before initializing UART.

However, I still see the UART signal in same waveform (no inversion). Any suggestions on how to set this register / any additional registers need to be set?