I too am frequently receiving the “Device Is Taking Too Long To Repond” error message after starting a Manual Watering Cycle. I only use the Manual Watering Function so I can’t say if this error affects programmed cycles or not.
I too have Strong Wi-Fi and the Hub plugged in on the inside wall a few feet away from the hose faucet or as close to the hose faucet timer as possible.
I was away on holidays for 2 weeks loving life thinking I could periodically start a watering cycle and I was able to for 2 days and then I couldn’t start another one for the rest of my trip.
The system worked flawlessly for a couple weeks and now it’s been nothing but issues.
When I came back from holidays I pulled the power on the Wi-Fi Hub, waited a few seconds, plugged it back in, waited 30 seconds and was able to run a manual cycle no problem.
In order to mitigate this issue I have now put a camera on the zone to see if the cycle has “actually” started and I have now plugged to Wi-Fi Hub into a remotely controlled plug-In Power outlet so I can “reboot” to Wi-Fi Hub remotely.
Not an ideal setup though!