Key binds is one of those scrollable screens that FancyMenu can’t reliably re‑layout. The options are rendered in a scroll area that disappears when you try to customize it, so forcing a layout on top of it often gives exactly the kind of garbled mess you posted.
You can try the experimental “Expose Scroll Area Content of Current Screen” toggle (menu bar → Customization → expose…), but it comes with a huge warning: exposing the scroll widgets removes the vanilla scroll area entirely and dumps all buttons in the top-left corner of the editor. It works only on very few screens and is mostly for debugging; it’s not a clean way to hide or delete entries like keybinds. In short, FancyMenu can’t really “remove” keybind entries because the vanilla system still draws them, so the safest approach is to avoid customizing that screen entirely.
If you really need to hide keybinds, you’d have to rely on a mod that rewrites the keybind screen itself or blocks the wrapper buttons before FancyMenu ever sees them. FancyMenu doesn’t offer a supported way to strip out keybind entries from that screen—customization will break the layout instead. For more on why scrollable screens are so fragile, check the Scrollable Screens guide: Customizing Scrollable Screens.