Annoying runescape interface glitch

I am experiencing an interface glitch on this account; It doesn’t happen on my other two accounts.
When I reload my My Custom 1, the chatbox and some interfaces around it mess up; I see my ability bar move like 2-3 pixels to the left and about 1 pixel up, pushing away the chatbox and slightly pulling up my ability book.
That adds a pretty ugly-looking 2-3 pixels gap between my ability book and the chatbox.
I save the interface when it looks fine, and for some reason, when I reload it, it messes up.

It also gets messed up when I log out and log back in.

If I keep resaving + reloading My Custom 1, the ability bar keeps moving 2-3 pixels to the left and 1 pixel up every time, so it eventually ends up at a very different location.

That’s the thing: my menu bar is on the top left in my interface.
The only thing that touches it is my stats screen, and it’s like that for my other two characters, which don’t get that glitch. :/

I tried moving my stats screen so that it wouldn’t touch the menu bar, then I saved and reloaded, the ability bar keeps moving several pixels up-left.