DataFilter groups don't seem to be working

I am attempting to use DataFilter with a DataList. Individual (top-level) filters work fine. But it seems that filter groups are completely ignored. Is this functionality not implemented yet?

When I iterate through the filters and output them to the console, I can see that the groups are properly populated and the filter parameters are correct. It just seems that they have no affect on the DataList if they are in a group.

Works normally on our demo: