Seems to be related to items spawning on the screen past the creation of room. The result is that money making game flips out entirely and renders one transaction per frame and don't seem to care to set the gambling state as being done or something, gee, I dunno. I have no idea how this works internally.
Here's a video: https://www.dropbox.com/s/jxvadkgm8sekli5/GamblingSim2000.mp4?dl=0
It's not exactly a complicated set-up I made this test quest in 5mins.