I have noticed the same issue but it's only been since the firefly blocker was changed recently, before that it would only shuffle if i couldn't match anything
Sometimes it will show me my rewards for passing a level and for example if i earned 3 stars on that game then i should receive 250 beans well sometimes it never applied the beans to my account, this happens pretty often
Since I'm not linked up with a c/c i can't buy anything the game doesn't come with, but i usually go back to levels that i didn't get 3 stars on and replay them