How does this magic item’s effect interact with itself? (Out of the Abyss)

In Out of the Abyss, the Maze Engine has a random chance of

The book includes a specific duration for this effect (until the end of the Engine’s next turn).

However, from the previous page:

How do these two rules interact? My first thought is that it would shut down immediately, but that would mean the listed duration can never be relevant.