Bad display of widgets in 2 columns view

brand new Studio project. It contains a "File" document, with some widgets in the "Summary" layout (see screenshot #1). 2 columns, the 2d column has LifeCycle, Actions, Custom actions, COmments and Tagging.
At runtime, there is a huge empty space between each widget. The "tagging" widget for example is at the very bottom of the form, so you miss it if you don't scroll (this was my original bug actually: "the tag wdget is not displayed at runtime )