Thanks for letting me know! Lightning Round only accepts answers from a bank of about 100. If the answer isn't in there, it doesn't clear the field or add the text to the list. "Haunted House" works, for example, but "Cheese" does not.
If there's something you think should be in the answer bank but isn't, let me know and I'll add it for version 2.0. I'll also add a sound effect and make it clear the field on a "wrong" answer!