RDC8445S mirrors images horizontally how can I correct this? Buttons on controller move axis in correct direction, image is not inverted on computer.

Hello, please check that the machine's original position and the laser's original position in the control panel are consistent with the software settings, and at the same time, ensure that the mirroring function on the software is not closed.

Since the arrow keys move the axis correctly, your wiring and motor direction are fine.
Horizontal mirroring on RDC8445S is almost always caused by machine origin or axis mirror settings.

Check these two things first:

1.Machine Origin setting on the controller
If X origin is set to Right but your home switch is on the Left, the output will be mirrored.

2.Make sure Mirror X / Flip X is OFF
Check both on the controller and in RDWorks / LightBurn.