@Ajay19uk 

Which Tapo light bulb do you have? This kind of thing usually comes down to a setting, an automation, or access control. Here’s a quick checklist of common causes to help you troubleshoot:

• Schedules: Do you have any schedules (timers) set for the bulb?
• Away Mode: Is “Away Mode” enabled on the bulb? Set Up Schedule, Away Mode, and Timer for TP-Link Tapo Smart Plug/Bulb/Switch in Tapo App
• Automations: Have you created any automation rules for this bulb that might be triggering it? How to create Smart Action (Automation or Shortcut) on Tapo app
• Third-Party Platforms: If your bulb has been synced to third-party platforms like Alexa and Google Home, it's important to check if any routines or automations set up there.
• Power Outage: Was there a brief power loss in your home? If the bulb’s Default State (in its device settings) is set to “Turn On,” it will light up automatically after power is restored.
• Shared Control: Could someone else be controlling it? Check if you’ve shared access to the bulb or your account, or if you’re logged into the app on another device that someone else might be using.