Describe the bug
The isNaN() function directly handles units and returns true for a NaN unit (eg: NaN ft). But if we have units in a matrix or an array (eg: [NaN ft, NaN ft, NaN ft]), it seems that the NaN unit doesn't get recognized, and isNaN() returns a matrix of false

To Reproduce

1. Run isNaN(NaN m) → it returns true, as expected
2. Run isNaN([NaN m]) → it returns [false] which doesn't match the behaviour for a regular unit that's not within a matrix.