One thing for sure, messing with
height of elements is a challenge because you are in competition with Bubble’s engine and HTML structure design. Re-sizing an element does not resize the parent
bubble-r-box and grand-parent
bubble-r-line. Parents and grand-parents may have several children (Bubble elements) so if you do address them with CSS you have to consider that other elements might be affected also.
As for the dimensions, 1640px is the default width, the one you entered in Bubble editor, but you probably also enabled the element to resize with page, so the 1920px value is the actual size of the element managed by Bubble’s engine.