@bmodleski Sometimes there is a ghost reading on the terminals. The .25 volts is no big a deal.
Now, the output of 26 volts on all zones when one is activated is. If the controller is trying to activate all zones at once, it won’t work. See what happens when you activate one of your zones that doesn’t have a wire in it. Zone 9 or 10. Check the output on the wires then.
Disable the sensor on the app. Try restarting the controller by unplugging for a few minutes and plugging back in. Let it reboot. See if it does the same thing.
If that doesn’t work, I’d contact support. They can troubleshoot the controller on their end.