Pagan reformation + Medium Crown Authority = vassal revocation clusterf#$&

My first ToG game. I started as Rurik, had some fun times with gavelkind (with my grandson inheriting the duchy of Novgorod and my son the 6 counties within said duchy – those opinion modifiers made for a seriously loving familial relationship), managed to survive bordering a runway Tengri Carpathia that stretched from Omsk to Bulgaria to Prague (don’t ask), unite most of the de-jure Russian Empire counties, get 4 of the 5 holy sites – things going well, in other words.

So, it’s 940AD, and I decide to reform the Slavic faith. Most of my Russian counts and dukes convert with me, the rest I force to convert, everything’s peachy. I switch to elective, everything’s still peachy. Now, I switch to Medium Crown Authority and the clusterf#$& begins. Half of my realm’s lower vassals (mayors, barons, bishops) are still Old Slavic, so their reformed lieges go on a crazy revocation spree. All the heretic Slavs are kicked out of their cities and bishoprics and are forced to scavenge for scraps on the street.

And here’s the problem: my count-level vassals continue to hold on to those revoked cities and bishoprics, in spite of the wrong holding penalty, and are not assigning/creating new vassals for them.

Anyone experience something like this? Any advice on how to handle it? Have a few hundred hours clocked with CK2, so not a noob, but am feeling like I’m missing something.