Issue with differential drive rover RC mapping

I’m trying to configure a differential steering rover and I’m having an issue with the PWM outputs. For some reason, the left and right motors are only controlled by channel 3 on my controller, and I cannot separate them to have my left motor be on on RC channel 1 and my right motor be on RC channel 3. I looked through the parameters, and I don’t see what could possibly be wrong. I reset all parameters and my Pixhawk’s settings twice, and I’m really not sure what to do. Thanks!

Video explanation: IMG_7170.MOV - Google Drive

My parameters: 25Feb24_RoverParams.params - Google Drive