What you were expecting to happen, and what actually happened:
Labyrinth map is poorly designed. Green room is actually not accessible and there’s no “maze” reason why you would have to do top left battle first. There is also no “maze” reason you have to fight purple room before mythic when taking the long way.
How often does this happen? When did it begin happening? All the time. I’m not sure how long the maze layout has been poorly designed for.
It’s possible that the map does not match the actual layout, or that there are physical impediments that make certain paths one way. Honestly, I think it was lazily programmed. This was already reported when it was released.