It has to do with the pace of the AI cars. They seem to behave properly up to 100%, but as you climb higher than that, the cars do roll more. That may have to do with increased cornering speeds. The fact that it is 'known' does mean they are investigating a cause and hopefully developing a cure. That does NOT mean it will be ready today.
The trouble is whether a bug is "known" or not is irrelevant to users who have spent money purchasing DLC that effectively becomes redundant, many bugs are "known" in all levels of gaming development but when urgent ones (such as this) come along then users have a right to question where the fix is. This is (in my opinion of course!) something that the Devs should be dropping everything for to fix with the utmost urgency. Not saying that S397 are not doing this as they may well be struggling here trying to debug this issue, but I've seen this lack of urgency in many games (including Sims) in the past decade - new bugs become "known" but no fix ever comes out of it or it's months/years later when it does. I hope that S397 are actively looking to fix this now and issue a hotfix as soon as possible, but if it drags on for a couple months then I'll be adding my name to the "well...where's the fix?" list, we're all fans but we're also all customers who've purchased items that need to work better.
