Unfortunately, that didn’t work. The transparent gap still appears on my Nexus 5X. Do you guys have an Android 8.0 device to test with by going to the live site? My only assumption is that it has to do with Android 8.0 since that is the only distinction between all my other phones, but then again my Nexus 5X is my only 8.0 device.
This is the only thing stopping me from buying a paid plan since it is worrisome to think a phone update can wreck havoc; especially since I would be hosting myself.
My only workaround is to add a thick shadow to the nav bar so that the line is not as apparent when the background page is white.
UPDATE: this line appears on all nav bar dropdown menus. I even tried a variety of free templates that you guys provide and they all have the transparent line dividing the nav bar and the dropdown so this is not specific to my site. However, the line still only appears on my Nexus 5X 8.0