2.6 - Blank Fields in Report Headers

After upgrading to 3e 2.6 (from 2.5 CP12 in this case), field values in the headers of customised reports are no longer displayed. The report below is displayed with filed values in 2.5 but after upgrading, Client Name, Matter Name, Matter Number and an unlabelled Key Word field have missing values.

The issue is resolved by moving the fields into the group sections, rather than the header. In most cases this can be done without drastically altering the displayed layout:

In this case the Key Word field, Client Name, Matter Name and Matter Number have been moved into the Matter grouping section and Currency Code moved to the Currency grouping section.

This new behaviour is welcome as having grouped values in the header is bad practice. The values displayed in 2.5 headers could be any of the distinct values that are returned from the grouping. It was not usually noticed in 2.5 as the reports are normally viewed for specific Matters, Clients etc. where grouped values are the same for each returned record.