Marking review as helpful/not helpful is not being saved

When I click on the thumbs up/down to mark a review as helpful/not helpful the app does react. But if I leave the app and come back to it, I see that it’s not been saved. Say a review has 50 thumbs up, I mark it as helpfully as well, it says “You found this helpful”. I leave the app and come back to it: the thumbs up are back to 50 instead of showing 51.