Unity 5 button navigation with keyboard and mouse

So far I've got button/menu navigation working well with keyboard arrow keys and whatnot, however if I were to use the mouse as well there are a few issues.

Mousing-over a different button doesn't un-select the one that was previously keyboard selected.

Clicking outside of the button deselects all of them and I can't re-select a default button by just going to the arrow keys again.

Mousing-over and then taking away the mouse doesn't leave the button selected, even if I haven't moused-over another button, just blank space.

Anyway I can sort of sync keyboard and mouse interaction like this?