I've taken screenshots of the moisture levels before and after adjusting the root depth on zone 1 (the grass zone that doesn't seem to be adjusting correctly) and zone 7 (the planter bed zone that does seem to adjust correctly) to show what I'm talking about.
These images show the moisture level in zone 1 with the root depth set at 8 inches.
So far so good. Now I changed the root depth to 25 inches in zone 1 and the moisture levels are as follows.
Okay, this is weird. Note how the graph above from June 2-8 changed. When I changed the root depth, it assumed that all the moisture is at the bottom of the root zone, which is incorrect.
Let's look at zone 7. Here is the moisture level in zone 7 with the root depth set at 10 inches.
So far so good. Now I changed the root depth to 25 in zone 7 and the moisture levels changed as shown in the following images.
Now this looks correct. When I changed the root depth, the graph from June 2-8 shows the moisture at the top of the root zone, which is the correct behavior.