I think it stopped working for a while and recently came back to life.

I also noticed a few months ago that I had stopped getting updates on any of my rentals. As a test, I booked a duplicate of one of my rentals at the highest priced company on Kayak and gave it to autoslash to track. I was just notified this week that they found an 80% lower rate. Of course, a lower rate was there all along.

This was a great tool. However, if they go offline for random undisclosed periods, I'll probably go back to checking rates myself.