I think you are misunderstanding what Find does for TArrays in c++.
If you have TArray<FTransform> Transforms;
Transforms.Find(SomeTransform); ← this will return the INDEX the transform is at in the array if it exists.
Therefore you now need to get the value at the index, like so.
FTransform TransformToFind = Transforms[Transforms.Find(TransformImTryingToFind)];