Cannot join Independence Movement; cannot declare independence.

So, I wanted to see what the game was like after stepping away for some months.

I'm playing Qara Unus (Afghanistan). Start as a vassal of Chagatai. Within a few years, all the vassals are at 0 percent loyalty, and one of them, Qocho, has started an independence movement.

I cannot join that movement because my opinion of Qocho is -28. Not their opinion of me, I spent years and years improving that so it's positive, but because "I" don't like "Them" despite us both being disloyal subjects of Chagatai with a mutual rival in between us, I cannot join the independence movement. Ok.

1352- They declared war, and now it's Chagatai and me vs every other vassal and their allies. Whatever, I'll just declare my own independence war. Nope-- can't declare war on Chagatai while I'm in a war with Chagatai. Ok.

So what's the deal? Can anyone tell me if I did something wrong or is this game actually that junk? Is anyone actually able to play this game?