-It seems USCIS felt confused because your I-129F is for your spouse's K-3 visa, not Fiance for K-1 visa. You had better contact USCIS to see whether happened.
Have you enclosed the copy of the I-130 Receipt Notice with your I-129F filing? If no, it may have made USCIS confused.
By the way, the I-130 and I-129F are two separate cases. But if the I-130 is approved first, and the I-129F is still pending, then USCIS will close your I-129F case, and only process your I-130 case for your spouse to apply for the immigrant visa, not need to process your I-129F for K-3 visa application. So, you may contact USCIS whether your I-130 has been approved. If yes, then it is normal for your I-129F to be closed.