here's a screenshot of the wp version and plugin versions I'm using.
the strange thing is I didn't add any plugins between when it was working and when it started being funky ... but now elementor is all over the place. I can't edit text editors, if i try to add a widget the widget disappears ... it's all buggy.
i ca't post my site url because i don't have enough posts to qualify ..
Are saying the white spot I see is the dropdown from the menu? Try to edit the navmenu widget style. Make sure the DropDown color is dark on all active, normal and hover actions. You may also want to place a divider just to test spacing.