Digikam - Group Images shows wrong count

If I go to an album and select a set of images to group and group them, when I hover over the group, it shows the wrong count of Grouped Items. It is always one less than the actual number of images in the group. Shouldn’t it show the total number and not expect me to count the displayed item as one and then add the number of Grouped Items?
An example is I select 6 images and right-click and choose “Group → Group selected here”, it only shows “5 grouped items” in the tootltip.