Sum discriminates letter case in view, but group does not

[Ratatosk]

I group users tasks by their email (Ansvar), and I found out that some of my emails were written with the first letter being uppercase. The grouping works fine, it does not discriminate between the letter casing, but the count does. Which leads to the wrong SUM:Timer (sum of the corresponding hours column)

[Steve]

Escalated.