I've encountered a strange situation with 2 fixes that seem rather unusual to me.
1: By removing the #MARGIN-30 tag and deleting the #Nav-bar tag under margin-3, the issue resolves itself when I reapply those tags.
2: Another fix is achieved by adding overflow:hidden;
I'm puzzled by this and wondering if anyone can provide insight into why this is happening. This is a first for me, as I have never experienced anything like this in my previous CSS projects or learning experiences.