iCloud sych very slow on my iPad 2, and incorrectly

The new iCloud photo environment works well on my iPhone 6+ and my iMac(2011). But it does strange things on my iPad. It downloads pictures very slowly when I click on the thumbnail. When I try to scroll through the thumbnails, it jumps around in my library and comes up with random pictures dating as far back as 5 years ago. So it is useless to me on my iPad. Before the new iCloud, I did a lot of work with my photos on my iPad. So Im disappointed. Is it because it is an older iPad? Any other ideas?