Here's a thing. To roll a 6 on a standard die is a 1 in 6 chance. But because of the laws of averages and deviations we know that you should regularly expect to roll the die maybe 10-15 times AND NOT see a 6 come up. That would be quite natural.
In Can't Stop when you are on the 6,7,8 columns there are only 104 dice throws out of a possible 1296 that will block you. That means you have approx a 1 in 12 chance of being blocked. By the same expectations of averages then you should regularly expect to be able to make up to 20 dice throws without getting a bad blocking roll when on the 6,7,8 columns yet you never can. So yes, it's definitely squiffy imho. Plus the number of times you progress well up the 6,7,8 columns before opponents have made any column and the system then constantly doesn't let you back onto the 6,7,8s is just farcical imho. They are the most common dice throw combos so you should be able to get back on 6,7,8 most times, but the system just deals you junk until the others catch up. Over and over and over.