Welcome to the forums! The reverse switch for models with the automatic transmission is part of the inhibitor switch on the side of the gearbox. It may not be aligned properly to sit in the 'Neutral' position, or it could be faulty. The first thing I'd do is raise the vehicle, remove the splash guard covering the transmission, disconnect the wiring connector from the inhibitor switch and measure the continuity between terminals 2 and 3 of the inhibitor switch by using a digital multimeter.
Move the selector lever to Reverse and check that continuity exists between terminals 1 and 4 of the inhibitor switch. Check that continuity fails when the selector lever is not in Reverse. If a fault is indicated, replace the inhibitor switch.
If necessary, select Neutral, loosen the retaining bolts and adjust the inhibitor switch until the arrow on the selector lever is aligned with the line on the inhibitor switch.
Good luck!