POST to /dataset/:name does not update the Dataset

I’m currently using the generate endpoint to get a new dataset, something like this:

then immediately POSTing that data back to the dataset endpoint:

with the exact object for the payload. The API returns a 200 response

From the Datasets view in the UI, it appears something has happened, as it now reads “4 minutes ago” in the Last Modified column, however when I look at the data, it is clear none of the data changed.
If I manually Preview or Generate the data from the UI, it appears to work.