@Suzanna21
Some people just don't review, and you unfortunately, got two of those guests right off the bat. I don't think there is any rhyme or reason to it. I've had a few guests who left me a really nice card/gift or a large tip but never left a review. And then I've had people stay for one quick overnight, who I never personally met, and they write me a 3 paragraph glowing review.
In the beginning your reviews are really important since they are going to attract more guests. You may want to add a message concluding the stay. Something along the lines of: "I am so delighted that you enjoyed your stay! I'm glad to have had the opportunity to host you. If you would please take a moment to complete a review, once Airbnb sends you the prompt, that would be very much appreciated. It will give future guests the confidence to book my place. Thanks again!”