Empty jsonFilters with identity filter

Hi there, 

I noticed that in some cases (see the example  below) after applying an Identity Filter (https://learn.microsoft.com/en-us/power-bi/developer/visuals/identity-filter-api), the jsonFilters of the custom visual returns an empty array instead of the array of the selected identities:

The content of the identity filter:

The result jsonFilters:

Can you verify it?

Thanks!