I created a project report and added a column for team member. I'm unable to sort by this new column when viewing the report within WF. I thought you could sort by any report column without having to export into excel? The code I used for the column is below.
So it looks like this is happening because you are referencing a collection, and with collections, it is not possible to sort the column. If you want to be able to do so, I'd suggest submitting an idea to the Innovation Lab!