Per the title, scenario events don’t trigger when they should (e.g. the fourth turn of the Outback Tycoon scenario, a settler should spawn on Coast nearest the Explorer the player starts with, and neither does the Gold Rush event trigger).
Aerdan and I tried playing a hotseat game of Outback Tycoon (the Civ 6 scenario) today. Unfortunately, the event triggers appear not to have happened, and OT relies on them to progress the game.
Specifically: finding gold did not trigger the Gold Rush eureka, and the turn 4 event to grant your first settler failed to fire. (No settlers means no cities means you’re stuck with just your starting explorer for the entire game.)
I am fairly certain this is not a bug in OT itself, nor in Civ 6’s hotseat play, as I am able to play a hotseat game of OT without PYDT and the event triggers happen.
Looks like this is a duplicate: Scenario events missing is from the other player who found this with me.
I’m not sure if there’s anything I can do here - the only modifications PYDT makes to the save file is to set player names and passwords. You say that it works fine in normal hotseat - could you try playing a normal hotseat game and saving/reloading after every turn like you would for PYDT and let me know if it works correctly there? I’m guessing it won’t work. 
I did several turns of a save/load hotseat game involving only my computer (a Mac) with no issues (triggered an Inspiration for Conservation), so it may be a cross-platform quirk. WC and I will be testing that sometime this week.
EDIT: Spoke too soon. I just completed turn 4 and…no settler spawn. So it looks like a bug in Civ6, not PYDT. Boo.
Specifically, it appears to be a bug in the Mac version. Aerdan’s playing on Mac, I’m playing on PC, Mac & PC can’t play online together (Aspyr’s been trying to fix this since the Mac version came out), so hotseat appeared to be the only way we could play together.