on MKV10z32 , (MCUxpresso- SDK2.2.0) , I am using hardware flow control on the transmitter (RTS_b) to control the Rs485 line driver.
UART->MODEM=(1<<(TXRTSPOL)) | (1<<(TXRTSE)) ;
but I realized that enabling the previous line is affecting the RXD line so no reception is taking place despite of that the signal on the rxd pin of the MCU is quite good and noise-free.
when theTXRTSE is disabled, and the transmitter control is handled manually. the reception is working just fine and the data is well received.