Biggest problem is that text representing bound keys shows on top of top menu background.
But it may make sense to make lower menu fully non-functional for while there is another menu on top of it.

I did actually fully rewrite all my GUI hierarchy a month or two ago in the malilib 1.12 code base (mostly here: maruohon/malilib@1f8fe2c and maruohon/malilib@8b2d6dd) specifically to prepare to properly fix these issues and also to give my GUIs a proper z-layered hierarchy, and to be able to disable the lower/inactive GUI functionality such as the config option hover tooltips while this advanced keybinds widget is open as a "popup-gui".

So yes I did notice that these are broken in the current 1.15+ versions, but I didn't bother spending time fixing them (yet?) as that GUI refactor was planned anyway. Maybe I should still try to see if there is a quick fix for this with a missing enableDepth() or adjusting some z-layers in the mean time before the 1.12 code lands to the other branches.

Here are a couple of screenshots with the GUI debug feature enabled, which shows info for the hovered widgets