@Heather970 They don't change reviews because a user is allowed to give whatever ratings they choose to without interference.
I'm not sure if you think the individual ratings are averaged to get the overall rating, if so, they aren't- the overall rating is a separate rating the guest gives.
I know it is a real head scratcher if the guest gives a lower overall rating when they've checked 5*s for everything else. But sometimes there might be things that aren't covered by the other ratings. Like maybe the guest found the bed uncomfortable, or it was a noisy area and those things made the stay less than ideal overall.
And sometimes it's just fickle human nature that has no rhyme or reason.
I did have a quick look at your reviews and while most are quite positive and you get complimented on your good communication and attentiveness to issues, I see 3 reviews in a row on one that while mostly positive, all mention that the bed sags in the middle. That mattress should have been replaced after the first complaint. This sort of thing can bring your overall scores down, and you do have some pretty low ratings on some of your listings. Cleanliness is also something you aren't getting top marks for, so maybe some new cleaners are in order.