I am running 3 zones on a Flex Daily schedule that is running every morning except for Saturday. When I view my zones the moisture level on 2 of the zones shows 0% moisture level and it shows it has always been that way even though I know the sprinklers are running. The 3rd zone shows a 52% level on the 21st and drops to 14% yesterday and shows the same today. I am confused as I know the zones are running every morning. Also I've never seen the zone hit higher than the 52%.
Flex is not able to keep up with the depletion you are experiencing everyday, so it is remaining at 0%. So all the water being put down is being depleted each day. I noticed your soil type is sand, which is part of why the water is being depleted so quickly. Have you tried to web soil survey to double check your soil type?
I just did they web soil survey and it showed what I suspected that I have sandy soil or loamy sand soil. The part that is confusing to me though is that all 3 zones are setup with the same soil type and grass type however they are still showing differences in the moisture level.
Take a screenshot of all three zones advanced settings.
What was reported for available water? That and the root depth settings will be the key to whether or not you can make Flex work without supplemental watering using a fixed schedule.
Were you watering more than once per day before you tried Flex?