I've found that when playing the new Thermal Update beta, the bio distillers stop working after a few days. I believe what's happening is for some reason when the slime stored in the bio distiller gets too low, the bio distiller doesn't consider it enough to produce algae with. However, since the bio distiller technically is storing slime, the duplicants will not deliver slime to it anymore. Hence, the bio distiller stops pumping/producing algae even with all other necessary requirements. This is quite annoying since oxygen is obviously the hardest resource in the game to produce consistently.
I attached a screenshot and my save file to this issue.
1. Construct a bio distiller. 2. Make sure it has power, an outflow pipe, and slime within a reasonable distance. 3. Set the bio distiller to the highest priority. 4. Assign all duplicates to only the "Deliver" job. 5. Wait 2-3 days.