I can't say whether 25 minutes is enough for your system or not. I don't know your setup or how much water evaporates on a daily basis.

The scenarios for when an alarm will reset itself ultimately depend on what ATO mode you selected. If the max on-time is not set correctly, it will not work correctly. Review your ATO settings. If need be follow along with the video and observe your ATO task in-action when you are able to. That will give you the best idea of what is happening. We've already determined the sensors are not the issue.