Sort on DateTime overruled by Enumeration?

I want to sort a list of objects on their DateTime in a microflow before putting it in a template grid, but it's displayed in order of Enumeration instead.

Some elements are hidden or visible depending on which Enumeration it is, could this affect the sort?

How can I fix this?

edit: I debugged it and it's not sorted properly in the microflow. I use a list operation activity and I only sort on DateTime, but the sorted list is still just sorted on Enumeration and not on DateTime.