Twine's so-called "randomisation" function seems to get stuck on favourite numbers (I've experienced this in another game I'm working on too) so you can have a run where you struggle to find the (or any) treasure, a run where one enemy dominates, or, as you experienced, a run where the treasure just pops up immediately. If I had had more time I would have written a more complicated randomisation script to try and circumvent this problem. I also had the intention to add a joke I wrote about finding an artifact early - on the chance it would happen - but I didn't have time to implement the code.
Thank you for playing!