How to PERMANENTLY turn off "Discovery Quests"?

I returned to the game after couple of months and there are some "new features" that ruined my game.

Every single time I try to load a game, I get immediately the annoying "discovery quest" popup. I end the quest. Go to the Game option. Disable the quests. Apply the changes. Return to the game. Save the game.

"Incoming Discovery Quest"

I disable the quest. The very next second, before I even have time to go to the menu: "Incoming Discovery Quest"

I go to the Game Options. It's DISABLED. I enable them again, apply changes, disable them again, apply changes.

I go to the game again. Save the game. 

"Incoming Discovery Quest" 

It takes about 5 attempts until I can actually play. But if I try to switch the household - there we go ALL AGAIN. 

Until I'm too frustrated. Save the game, exit.

The next day, "Incoming Discovery Quest"

Is it meant to be that way? Or is it a bug? It made the game completely UNPLAYABLE. (Yes I do have lots of mods but I did already try to remove them. Nothing changed.)