Did you keep in mind the iOS review is only showing for the specific country? So if your Apple ID is registered in the region of the USA your 5 star rating will only show in the USA, but not in Germany, Australia oder somewhere else.
Also, it takes up to 3 days for them to appear from my experience. If you are the app developer you can download the App Store Connect iOS app and check the ratings of your app. You will see them all in one place - from all countries.
For Google Play, they will show you ratings/reviews from all over the world. Thats why almost all apps have way more ratings/reviews on Google Play than on the Apple App Store.