If you open up inspector and click on the window that you want to have enlarged, where does the inspector tell you that the height is based on? I opened a popup and tried to find the element and found that mx-dataview-content got the job done:
modal-dialog → modal-content → modal-body → modal-placeholder → row ->mx-dataview → mx-dataview-content
I have set all of these to height 800px, then it worked. Maybe you only need mx-dataview-content, when it is inside its parent classes of course. We don’t want to mess it up anywhere else.