@JEBariffic, sorry for the delay.
I reviewed all of your zones and believe I've spotted the variable. Zone 1 (Garage Grass) is setup with Some shade, whereas the other zones on the Flex schedule are setup with Lots of sun.
As such, the ET will vary, which impacts the moisture balance (loss). For example, on 8/29, Zone 1 (Garage Grass) recorded ET of_.13_, whereas the other zones on the Flex schedule recorded ET of .16.
Tomorrow's watering of all zones aligning is due to all of the zones approaching a 0% moisture balance on the same day. This will likely happen on a irregular basis.
I believe this is due to the two drip zones setup on the Flex schedule as Smart Cycle is disabled for drip nozzles (emitters, bubblers, misters). There's a few work arounds; 1) setup a separate flex schedule for the drip zones, or 2) create a custom nozzle for the drip zones and "fake it" by setting them up as lawn nozzle (fixed spray head, rotor head or rotary nozzle) with a low precip rate
Hope this helps!