Is still an issue for you in your game?
And the holder of the provinces are Greek as well?
Looking at the conversion events, I can't see any reason for why they shouldn't fire if you fulfill all the conditions. I think it would be best if I could look at your save game, check the current setup and see if there is anything there that could cause the issue. If the game is an ironman save located on the Steam cloud you should be able to find your save game at the following location, or a similar one depending on where you have Steam installed etc:
C:\Program Files (x86)\Steam\userdata\<YOUR STEAM ID>\203770\remote\save games
And the holder of the provinces are Greek as well?
Looking at the conversion events, I can't see any reason for why they shouldn't fire if you fulfill all the conditions. I think it would be best if I could look at your save game, check the current setup and see if there is anything there that could cause the issue. If the game is an ironman save located on the Steam cloud you should be able to find your save game at the following location, or a similar one depending on where you have Steam installed etc:
C:\Program Files (x86)\Steam\userdata\<YOUR STEAM ID>\203770\remote\save games