I don’t think Harry ever wanted to leave, he clearly dragged it out when Megan was pushing to go, from what he said, and the half in Half out would have been him wishing to stay royal. But Megan was going. That was it, she was going, and he had to pick. And he picked her,and avoiding a battle over custody. He wouldn’t have wished the kids raised without a mother, and he’d not wish to be a part time dad. I don’t think he realistically had another option but to go with her due to the kids.
giving him security I think is solidifying his royal position, that even though he’s left and isn’t a working royal, in his mind, if he had the security he previously had, it would have shown he still had his position. Removing it says a lot about his reduced position. And that’s what’s hurting him.
the fact he’s lost so much on leaving is caused much of his spiteful behaviour, the fact the royals would not let them do what Megan wanted, to monetise it.
he is clearly a very unhappy man, who lashes out without thought and behaves in a spiteful and malicious manner, and I genuinely doubt Megan is much happier as they have failed so drastically and publicly in what she was hoping to achieve in the states.
but yes I think the security fight, is at heart about him wanting his position as he sees it recognised,