Huh. Sorry, but I got nothin’… Wait… go into Irrigation → Zones → <whatever zone> → Edit → Advanced and check the Nozzle Inches Per Hour (NIPR). Are they the same? I would expect so, since you configured them both as rotary, but…
In fact: Check all the Advanced settings of each. There has to be something in there to change the calculation. The Rachio 3 may be complicated, even arcane-seeming, at times, but it’s not arbitrary–at least not IME.
Ok great, maybe zone 2 was updated by accident somehow.
Flex monthly does not water every day, the calendar will show how each month will changed based on time of year. If the frequency looks ok, but the minutes are still too high, I would just lower the recommended minutes.