TWebClientDataSet.Rows nil items


I have TWebClientDataSet without connection, that I fill at runtime.
On TWebDBGrid everything looks fine, but when I read Rows, I get at the beginning
many nil items (about the same number of data rows that follow).
Currently I solved it by just deleting nil items from Rows after getting it,
what do I miss here?

Example (shortened, it had many more items):


I have no idea how you fill the dataset. When I check in our demos & test apps, WebClientDataSet.Rows, it returns the JSON array of the data in the dataset.
If a problem persists, please provide sufficient details / sample project to allow us to reproduce this here.

Do you set MyClientDataset.Active := False before loading the rows?