@gustfuchs, hello from Denver! Thanks for reaching out. Looking at your Hunter controller wiring, I believe you have everything wired correctly. It might be worth separating the two common wires you have in the left white terminal on the Iro, and put the black common into the right white terminal. The common terminals are made to work regardless of what side you connect to. I'm curious if you don't have a secure connection for the zone common wire.
If this doesn't do the trick, could you please send us some photos of your valves and solenoids? We'll need to check their electrical requirements.