Your code is not exactly correct, your recursive call is not right.
Try adding something like this in your local IDE: console.log("For n=9266, my solution returned: " + SubtractSum(9266)); and see what happens.

No. The test is fine:

v  v v  v   v      v v v v   v      // symbols: 10
@mw>0=QD-iAx!rp9TaG?o&M%l$34L.nbft
    ^          ^          ^^        // numbers: 4

0 is a number, not a symbol.