The serialRead example work for me without issue at 9600 baud (didn’t check other baud rates yesterday). I’ll test serialWrite again tonight to be sure, but I’ve never had an issue with it in the past nor with any baud rates under 57600. Higher baud rates (> 57600) do not work with SoftwareSerial.

Are you setting the correct baud rate for your device and wiring RX on the board to TX on the device and vice versa?

Also, which Arduino board and particular serial device are you using?