As shown in SS above i passed the test with totally inverted logic than stated in the challenge. This bug only appears when all three slot numbers are equal.. i.e. you win, in which case you should actually return the number rather than null that this code will return.
Also to mention that instruction also says: "If all three numbers match, we should also set the text "It's A Win" to the element with class logger." which is not done or checked and you still pass the test.