The user manual says on page 358
"To set the properties of a report/presentation band ....click on the band's bar in the Design Area. The properties of the selected band will be displayed in the Selection Properties window . . . .
Height
Specify the height of the band in points. Note that you can also drag the band's bar in the design area to change the height of the bands on both sides of the the bar being dragged"
This does not work. In fact I can change none of the properties by direct entry in the Selection Properties. It allow me the change, but will not save the new values.
So far I have struggled by solely using the design area (hard work!) but . .
So far as the Summary Band is concerned I can't change the height by dragging either. The issue with the Summary Band is made much worse because there is not a band below it which could be dragged. If you drag the line at the foot of the design area, it has no effect at all.
I saw some posts dating back to 2017/18 (I think - I can't find them again despite using the same search criteria) in version 8.4 of similar complaints. I am using 8.7 (Build 3012)
Really rather urgent