Glo Glo is slower than touch

I found my Glo is slower than touch when I open the book.if I open book on main screen,it's slightly slow and noticeable,if I click library-book and open a book,the glo is very slow,feel like frozen.this happened on 3.2 and get worse in 3.3.turning page no different,they have same books and side load ePub


Any thought?

Thanks