Diagnosis
This is a known hardware limitation of the L530E model. The bulb has a minimum brightness threshold; it cannot achieve 1% dimming like some higher-end models.
How to Fix It
There is no software fix. The lowest achievable brightness setting for the Tapo L530E is approximately 10-20% of its maximum lumen output. You must adjust your scenes and schedules within this range.
If That Didn't Work
If the bulb is stuck at a specific brightness higher than 20% and won't respond to slider adjustments, perform a factory reset via the physical switch (off/on three times) and re-pair it to the app.
Heads Up
Attempting to use third-party apps or Alexa/Google routines to set a '1%' value will default to the bulb's internal minimum. This is not an error.