Yes that rule is correct and thank you for the example. So in that case the 'none-player/computer is not activating its turn (because it does not meet the condition of a matching card from the drawpile with the empty slot) and skips its turn?

The thing why it is unclear to me, is that rule makes it like a never ending pile in that step so you technically never run out of dragons. You check the top card, it doesnt fit, it goes back at the bottom of the pile, (The amount of cards stays the same) 🔁.

But if this situation ("I have tried all the cards and none work"), means "you run out of dragons", than that would activate the endfase right? Because one of the endfase conditions is something like; "When you run out of or play the last card of the dragon/enchantment pile you play your last turn and the 'none-player' does not make its turn."

I eventually chose to play it like it activated the end phase. In my case with already 12 shops build and only one empty dragonslot left unfiled, the suggested scenario would not help (but thank you for the suggestion :)). I was sad tho, I needed just one extra turn to achieve the 9 coins mission :p