This can have various reasons: Your product must be at the right time to be able to trigger the automation. Each time you switch off the light electrically, your product will lose its time-information. To retrieve the time, your product must be connected to your smartphone (within the range of the product - Bluetooth)
You haven’t selected a day for launching the automation or the time has already passed and the automation will be launched next time the time slot is met.
You haven’t set recurrency, it means the automation will be launched one time at the set days, and will turn off once executed.
You haven’t enabled the automation, the data is saved but the automation is disabled