How are people selected to be invited for Hunts?

It's happened more than once that my heir won't show up on the invite screen even when I select every category or when I deselect all categories except Close Family. I look at their character and they're in my capital, not traveling, so they should be invited right?

Are certain court/council positions exempted from Hunt invites?

and on that note what about other positions? I have an heir with good martial stats I want to make my Caravan Master but he won't show up. It's so annoying that the game never explains this

edit: so just did another hunt and my Master of the Hunt wasn't even included in the invite list. He's just chilling at home and he wasn't even invited. Wtf???????