When Dithering launched, it was a part of the same feed as Stratechery; we separated Dithering and Stratechery into two feeds shortly thereafter.
Unfortunately, if you subscribed to Dithering in that time period, and later add Stratechery, your feed switched, and you need to re-add Dithering as a separate feed. We apologize for the trouble, and are working on a more permanent fix for this situation.