When adding a font.pointSize property changes on the listview's active item, the current item of the list is not displayed anymore when scrolling down

See attached file.

I try to increase the font.pointSize of the selected item of the listview. When adding this line:
PropertyChanges

{ target: itemText; font.pointSize: font.pointSize+3 }

for the first bottom listview, the selected item is not shown anymore when scrolling down the list with the up/down arrow keys.

Strangely, the scale propery change does work well.
PropertyChanges

{ target: itemText; scale: 1.2 }

Moreover,
If I uncomment the line "//height: 20" in the delegate component, this shows correctly the current selected item when scrolling down. But, I want to avoid fixing the height property because I want the cell to automatically set its height according to its contents.