Mine came in earlier today and all keys fit except for the spacebar. The stabilizers for my quick fire rapid are too thin for the spacebar so it doesn't press evenly. Every other key with stabilizers fit fine
BrangDingCommon problem with aftermarket keycaps. Easy fix is to get a little square of plastic food wrap and put them over your stablizers so they are more snug in the keycaps.
Should be good to go after that.