Thanks for the info. We're actively reviewing this. Could I please get you to take a look at what another user has done here to solve it and let us know if you think it might be the same root cause?

Hey david,

Are you saying that every time you launch the game fresh, you only ever have chapter 1 available until you click continue sandbox, then quit to main menu, and get chapter 2 available? 

Thanks Vince! We've reviewed the bug report including the save you were last playing and can't see any obvious issues sadly. Would it be possible to record a short video of the stuttering?It might help us understand exactly where and how it might happen.

I'd think this one is resolved by now with the latest patch. Is it still an issue for you?

Thanks a lot for recording that video mate. We're looking into this as fast as we can!

Hey Shaun,

Sorry about this - We'll try to get this fixed in the upcoming patch within in the next month.