This type of grid is very difficult to create error free. Unfortunately this is fundamentally flawed. There are at least 15 other correct solutions. All and Andy can swap. All and Oat can swap. Ear and Rain can swap. Andy and Art can swap. Using only one swap creates a further 4 solutions. Perming any 2 from 4 creates a further 6 solutions. Perming any 3 from 4 creates a further 4 solutions. Using all 4 creates another solution making 15 additional solutions.

Pretty much what Eagleeyes said - great idea but there are too many options.

Nice job!

Knew what to do but couldn’t quite do it but it was alright

I thought this was a good idea but, as has been pointed out, too many crossovers and the use of such common words and letters means there is no unique solution. Of course, it will be possible to produce such a grid where there is just one solution with perhaps up to three crossovers in.