Rating UI has a problem on iphone

[momogame]

When I try to rate using iphone, after I rate the first criteria and try to rate another criteria. The previous rate I rated is disappear.

[momogame]

From this picture, after I press 5 star on Ease of Use and try to press another 5 star on Reliability, the previous 5 star on Ease of Use is gone.

[momogame]

I found a solution that instead of press a star, you need to drag it instead.