Why zones are scheduled to run at different durations?

I have 4 zones set up with identical parameters, like soil type, sun/shade, root depth etc. with only one difference, zones 1, 2 and 3 have rotor heads while zone 4 has rotary heads. Areas of the zones are about the same.I set up a flex daily schedule to water all 4 zones in one run. Due to this morning’s thunderstorm, now the soil moisture in all zones is 110%. The frequency of the watering is every 3 days so that’s good. What bothers me is the watering duration of each zone. 2 of the zones are going to be watered for 58 minutes (1 & 2) while the other two (3 & 4) are going to be watered only 38 minutes in each run. This is constant out to September. Why do 1 & 2 get more water duration than zone 3 and why does zone 3 have same water duration for zone 4? I have to emphasize again that the parameters are very alike across all zones.

Very alike and exactly alike are two different things for Rachio. If you post the differences, someone on the forum may be able to help.

FYI, the area is not used to calculate amount and when to water. It’s only used to calculate how much water you use. for me, I just ignore it.

Ok so they are exactly alike except for types of nozzles.

https://support.rachio.com/hc/en-us/articles/115010379707-What-type-of-spray-head-or-nozzle-do-I-have- Different sprinkler heads provide different amounts of water.

Yup, I got that but my zone 3 has same nozzle type as zone 1 & 2 but its water duration is only 38 minutes versus 58 minutes for zones 1 & 2. This 38 minutes duration is the same as zone 4, which strangely has different nozzle type.

Zones 1 & 2 : Rotor nozzles : Water Duration 58 minutes
Zone 3 : Rotor nozzles : Water Duration 38 minutes
Zone 4 : Rotary nozzles : Water Duration 38 minutes