If two consecutive lines have a tag, the CSS effect gets overlapped. Maybe the height of the rectangle for can be reduced or the line height can be changed?
Screenshot for reference:
I tried to get them to fix this years ago, but they're strangely opposed; the fix is "don't do that". I wish they would just give us nice-looking kbd tags. I'll poke somebody at Stack Exchange to see if there's any chance of that happening. Since this is status-declined on the main meta I'm going to mark it the same here