I am seeing the same issue. Once in a while, my app does not export e.g. blood pressure correlations. Even though in the same run I also export heart rate samples, which are successful.
The strange thing though, is that on the Apple Health dashboard, I DO see my measurement. And I also see it in the chart! But when I go to Show All Data, the measurement is not shown. And if I look in Data Sources & Access, my app is listed as 'Inactive'.
Deleting and reinstalling the app helps to often solve it. But now I have my app exporting blood pressure fine, but still my app is listed as 'inactive'!
I recently rewrote the HeatlhKit export code of my app, in the hopes of (amongst other) fixing this issue. But the new code does the same as the old code, with respect to inactive data source.
I have no clue what's going on. But I think there is some serious bug in the Health App. Anyone can shed some more light on this?