I believe the Defer and min time statements are programmed by the task.I did a google search on your issue and came up with this informative thread:
Slider changing from AUTO to OFF on its own
I have a new Apex 2016 and have been controlling it through Apex Fusion for several weeks with no problems. This morning when I woke up, I saw that my sump water level was low, so I checked Fusion and saw that my ATK pump slider was set to "OFF" rather than "AUTO". I checked the Fusion logs...forum.neptunesystems.com
I didn’t know this, but it sounds like the sliders can be changed manually and by “when” statements. So the culprit is likely your when statement. Either it is just too short for your needs, or is signaling something wrong with your pump/tubing/etc that makes it so that it can’t finish topping off within 5 min. Also I’m not familiar with the way you are using the muliple defer and min time statements, so there may be a conflict there worth checking out.
But yes, I believe if the atk shuts off from the when statement (pump on for more than 5 min) it will throw the slider into off mode. Its not super clear what triggers an ATO error and what doesnt.