Custom Toolbar Questions

Hello, I’m trying to create a custom toolbar for LibreOffice and I cannot get some of the buttons to display the correct shortcut when hovered (tooltip). I have one set for F5, but it shows F3 for example.

I’m using Mint 17.2 xcfe edition

The shortcuts are correct, and the buttons work, but I find it annoying that the tooltip says the wrong key. It’s not happening on all my keys either, just a couple.

Any idea what is causing this?