Dust Achievements not Updating

[microcake]

I was playing Dust when I was at an airport and the lack of connectivity kicked me offline. I had turned off Dust while it was still offline, reset Steam, and continued playing but none of my achievements I got during Offline play got updated. (One Last Wish, The Stuff of Legends, and Baker's Dozen.)

Any known way to fix this on Macs? I also have a gaming PC if there are easier fixes for that platform.