Help with a zone that won't start

I’m stuck and looking for some expertise. I have a Gen1 with 8 zones with hunter solenoids.

One zone (zone 2) will not start watering but all other zones are working fine.

I can manually start the non-working zone by turning the solenoid at the box in my lawn.

What I’ve tried:
Swapped Zone 1 wire for Zone 2 wire to ensure the zone on the rachio is not bad. When I hook up zone 1 wire to the zone 2 connection on the rachio and activate zone 2 from the app, the zone runs correctly.
When running zone 1 in that configuration from the app, the zone does not run.

After that test - I moved the zone 1 and zone 2 wires to their proper location on my Rachio.

Tested resistance on the circuit - connecting my multimeter to zone 2 and the common wire - 25-26 ohms - which as I understand indicates the circuit is fine.

What am I missing? I have power (verified by swapping wires at the controller). I don’t have a short (verified with my multimeter on the circuit). I don’t have a mechanical problem (verified by manually activating the zone at the valve box).

What should I try next?

Sounds like you are testing things properly and the ohms are in the correct range. I presume that you tested the resistance with the wires disconnected from the controller, is that correct?