I noticed that "Count of Vehicles" was on Label on your first pie whereas % of trucks was on Label on your second pie.
Maybe what you attached is just an example, and "Count of Vehicles" being on Label serves some purpose on the donut in your actual workbook, but in this one it seems to be either layered underneath or completely absent, so what I would do is either take Count of Vehicles off of Label entirely, or if you want to have both numbers, add it to Label on your second pie (AGG(MIN(0)) (2) so that both numbers are visible (I've done this in the attached workbook)
vehicles.twbx 4.4 KB
That was done intentionally. When the percent is not 0% or 100%, I need [Count of Vehicles] displayed outside the donut chart to show counts for each [Vehicle Type]. My true dashboard contains the total count inside the dashboard next to the percent however I didn't add it here to keep it as clean as possible.
The issue remains, when selecting [Vehicle Type] "truck", the measurements are stacked on top of each other inside the donut. Selecting "all" and "car" both display as desired.