I have a combination of ge z-wave switches, outlets, and dimmers in my house. They all exhibit some extent of delay, but typically not more than 1 second. I recently added a ge zw3005 dimmer and if it has been in the off position for more than a few minutes, there is a 3-10 second delay when turning on the light. Turning the light off is always near instant. Subsequent toggles (on and off) respond almost immediately. But if I leave the light off for several minutes - again the 3-10 second delay returns.
This behavior is shown no matter where I toggle the switch from - physically on the wall or from the SmartThings app.
I’ve tried moving the hub about 10 feet from the switch, but this made no difference in the response time. I also tried repairing the z-wave network which also had no effect on the problem.