Yeah, that's something I'm trying to fix. It was less of an issue with my old dice roll detecting method. But I should be able to get it sorted. It's something that's quite difficult to test for because of how randomly the dice are thrown.
If you want them to always flatten out once you detect the side make the opposite face super heavy and lower play field friction so all dice get slide away, It looked like you using a 3D rolling area so this should be a fix.