Having the same issue. Code works perfectly in playgrounds, but I keep getting the timeout. Timeout has been an issue on all the swift kata I've tried

In swift, the comment is breaking the kata. Keep the comment and code times out . . . remove it and it passes every time

The test code they're running through yours is hidden and probably causing this to happen on purpose. If you get rid of anything that would cause a "null" or "undefined" value then you should be good to go