Can't secretly convert to Zun through Holy Site?

[Amorenkaire]

I'm trying to figure this out, it seems that it might be something that HIP changes but I can't find the information on it.

Doing a Zun game as Rutbil, and I can secretly convert to Zunism as my first liege. However, after his passing (and failing to induct the son into the faith through the secret religion event) my heir doesn't seem to have the option now. I still see the option to convert to Buddhism or Sunni Islam from the two counties that contain the Zun holy sites, however.

Looking at the decision file, last game I found out that I couldn't do it because I was a king, however this time my character is still a duke (with the titular duchy Rutbil starts with) and its still not allowing it. What condition isn't being met, and where is that controlled, if anyone is aware?

 

[HandicapdHippo]

however this time my character is still a duke (with the titular kingdom Rutbil starts with)

What? You aren't a duke if you have a kingdom.

 

[Amorenkaire]

What? You aren't a duke if you have a kingdom.

Sorry, that was a typo. Its a titular duchy title. The rest of my titles are counties is what I meant to imply there.

 

[Militantti Talitintti]

This is not about Zunism but I'm not able to secretly convert through controlling Baghdad either? Is this mechanic disabled in HIP or am I missing something. I'm not zealous nor a religious head.