These review apps sometimes have error with importing reviews. Especially with Ryviu when it can't auto update reviews which lead to new reviews being missed. There are other review apps you can use. If you import products from AliExpress, you can take a look at Ali Reviews . This app can bulk import authentic reviews, and it can auto update reviews also. All new reviews will be auto imported to your store, so you don't have to waste your time. This app also provides free time trial, so you can take a look and try without fear of wasting money. Wish you best!
@hello-beauties- please make sure that section belongs to Ryviu, as I know, review section of Ryviu always appears at the bottom of your product page so default reviews section that are saying no reviews can belong to another review app.