Are you sure? The only diagnostic I see is printing "@args\n", which stringifies the array, making it impossible to tell whether you have 4 elements or 1. That's why I suggested that you check the array size.

For the record, I did try the join() before trying to send the array by itself since it made sense to me that execute() needed separate args.

Are you sure there aren't lingering traces of this join() in some other place in the code? Lingering traces of prior code experiments are a frequent source of bugs (mine, at least).