Seems like something new introduced with the latest update. Last night our online game, everyone was noticing that sometimes 2 or 3 of the dice weren't rolling with the others. It seemed to me that it happened after the app sat idle for a long period. The first roll, only half the dice would roll. If you did it again then everything was fine from then on out, until it sat idle again for a long time. Then it would happen with the first roll made again.
The setting we all had at that time in common, was the auto scoring. Everything else varied settings wise. I'm going to test it out again tonight and leave it sit for a while in between rolls to see if I can recreate it, then turn off the auto score and try it again. Not sure if that is the culprit, but it's the one thing all the apps had in common at that time. Never had this problem prior to the last update.