Understanding the 15-minute delay to establish the light level is correct

To prevent the door from opening or closing unintentionally due to torches, headlights, security lights, shadows, or similar brief changes in light, the detected light level must remain above or below the set threshold for 15 minutes before the door will operate.

If this process is interrupted, meaning the light level falls below the opening threshold or rises above the closing threshold, the 15-minute timer will restart.

For more details, read this more detailed explanation: What does light level mean?