R5: Every time I have a new son, I set up a duchy for him and land him to keep my primary heir's succession nice and simple. I conquered a nearby duchy and set up my latest son, and then one of his counts deposed him, look his land and his duchy title. So I created a claim on the duchy, arrested the new duchess and took all her land back. But now I can't interact with my son at all, can't grant him land, can't disinherit him because he's "not in my realm" despite sitting in my realm, and can't invite him to court because he's a child. And then immediately after this he buggered off to Arabia so now he's too distant to interract with at all. But he still stands to inherit a huge part of my land. Worst part is I'm his guardian, too.

This is why I refuse to play ironman, honestly. Stuff makes no sense.