I know its rear wheeel drive but I had a similar problem a few years back in a granada. Turned out to be 3pence roll pin had sheared, had to remove box on RWD but if similar may be possible to do in situ in a FWD.
Probably the same thing TBH. Can't remember if it's solid linkage with pins or cable on these though
I read Dave's message as saying that the gearbox end (the shift rod assembly) still moves in & out of the gearbox when you waggle the stick, though..
Although if he meant that it moves at that end fine, but he hadn't had A.N.Other person waggle the stick, it could just be a roll pin in the gear lever assembly .. which would be easier!
On the Granada the roll pin was inside the box, where the selector rod went forward from the lever into the box. Just had to remove the top plate as I recall, drive out broken pin, drive in new pin, all sorted.
And the symptons where lever moved very freely, and the linkage all appeared to be good, removed top cover and the roll pin was obvious. My luck was it broke when changinf from 1st to 2nd gear and I was stuck in neutral. If it had stuck in a gear at least I could have driven it home

HTH