You can't appoint someone to be 2 patriarchs at the same time, but they can become so on their own

[Roparex]

So this dude is patriarch of rome and bulgaria.

It might be because the viceroy of bulgaria is the viceroy of italy so the autocephalous churches have the same leader?

 

[taxintoxin]

Might it just be that one is the religious title and the other is the variation of the court chaplain position?

 

[Gans]

For kingdom titles which are not assigned to any Pentarch seats, the Ecclesiarch is the Patriarch. Nothing strange here.

 

[SigurdStormhand]

Pentrarch Sees seem to be a bit bugged in some circumstances. If you look, that Bishop is Metropolitan of Rome and Patriarch of Bulgaria - the game doesn't recognise him as Patriarch of Rome. I had an odd thing once where, as Exarch of Italy, I had to have the Patriarch as my Ecclesiarch, or I couldn't Excomunicate anyone.