I would troubleshoot in this order:

If the shift lever feels sloppy, check for loose or missing screws (4) that hold the two clamps for the shift shaft that runs down the top of the column. These occasionally loosen or fall out at higher miles. Remove the plastic column trim to see the shift shaft.

The adjuster for the shift cable is at the transmission. If it has never been adjusted before, it may need to be tightened slightly.

There is a separate, much smaller wire cable that goes to the gear indicator in the cluster. It could be broken or out of adjustment. There is a thumbwheel under the dash to adjust it but you may have to remove the lower dash trim and knee bolster plate to find it.

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2003 FX4 Level II, Supercharged 5.0L V8, Headers, Duals
BW4406 manual transfer case, Aussie Locker, Torsen L/S, 4.10's
Bilstein 7100 rezzies, Cadillac/Mustang rear discs, Duff traction bars
Keypad Entry, Lock LEDs, ABS switch, sway bar discos
Heated seats, Explorer EATC, Trip Computer and consoles

2003 XLT 2.3L M5OD-R1 reg cab, 2011 Taurus SEL, 2016 C-MAX Energi Plug-in Hybrid