Reads like a roll pin has sheared off
5 speed trans will have 3 Shift rods, 1-2, 3-4, 5-Reverse
Each shift rod has a slot piece for the shifter, and that slot piece is held in place on the shift rod with a Roll Pin.
Shift rods also have a shift fork held in place on shift rod by a roll pin
Neutral is when all 3 slots are lined up in the center, you can slide the shifter back and forth full range side to side.
When you select a gear, 1 shift rod is moved forward or backwards by the shifter, and it no longer lines up with the other 2 slots, so you can't move it sideways until you move it back to center, Neutral, and slots again line up, this prevents 2 gears from being engaged at the same time.
It reads like slot on 5-R shift rod became loose, roll pin issue, and now shifter can't reach slot to return it to Neutral.
First thing would be to remove the shifter and look down inside, to see the slots and then see if you can move them with a screw driver, or long bar, back to Neutral position, put blocks behind tires, and push truck forward or backwards to take any weight off the driveline/transmission so you can shift it manually
Look here for removal:
http://www.therangerstation.com/how-to/transmission-transfer-case-driveshaft/shifter-bushing-replacement/
Last picture there shows 2 of the 3 slots lined up from that pictures angle, you can see all 3 with shifter removed, looking straight down the hole
There is a top plate than can be removed with trans in the truck, but some cutting of floor plate may be needed.
Picture here of top plate, upside down, so you can see the shift rods, roll pins and forks:
https://www.ford-trucks.com/forums/1173238-m5od-shifter-fork-wear-diagnostics-pics-inside.html
And roll pins can be replaced with top plate off.
Could be just the shifter bushing is very bad, but long shot on that with description of problem.
And it could be something wrong in the transmission for 5-R
Roll pin issues are not common, but with Rangers the hydraulic clutch does tend to get air in it, when that happens drivers get pissed off and FORCE shifter into a gear because clutch is not fully released, and this puts alot of strain on the roll pin for that gear, that shifter is a long lever so puts out alot of force at the other end