Am I missing something regarding rebels changing official religion?

[Terixis]

I'm trying to collapse to Zoroastrian rebels to convert to Zoroastrian but collapsing to them doesn't convert me. This is actually the second batch of rebels I'm trying to collapse to, I already collapsed once to them and it didn't convert me, it just gave me the same maluses in this screenshot. Please send help.

 

[Terixis]

Nevermind, I'm dumb, it's based on development and not provinces. Which is kind of annoying actually since rebels sieging down 50% of your low dev provinces and not the high dev ones is useless.

 

[Vulkandrache]

it's based on development and not provinces.

Im still hoping that gets reverted again.