StyledThemes on "[Theme: Celestial - Lite] Mobile content not displaying correctly - (Celestial Lite theme)"

Actually I do...and it looks like my fault. The HR styling in the theme's style.css has this around line 309:

hr {
	background-color: #ccc;
	border: 0;
	height: 1px;
	margin: 24px 0;
}

For firefox, it should have this added to it:

clear: both;

So if you are running a child theme or have a plugin that allows you to add custom css, you can add that missing clear: both; part to it.