Using Keyboard Focus for Dialogue Systems

I have keyboard focus working for my first set of dialogue questions with an NPC.

However, after the NPC has responded, and a new set of dialogue options are available to the player, the keyboard focus is lost, the arrow keys control player movement again, whilst the second set of options are still on screen. I tried setting up keyboard focus on one of the second set of buttons (button 4) but it’s not working, and I’m out of ideas.