Hi there Twinton,
If automations aren't being properly deleted from the Home app, first ensure you are following these steps from Create scenes and automations with the Home app:
Turn off or delete an automation
To enable or disable an automation:
1. Open the Home app on your iPhone, iPad, or Mac and go to the Automation tab.
2. Tap or click the automation.
3. Turn Enable This Automation on or off.
Tap or click Turn Off to choose an amount of time to turn off accessories in an automation. For example, if you create an automation that turns on the lights when you arrive home, you can have the lights turn off after an hour.
To delete an automation, tap or click the automation, then scroll to the bottom and tap or click Delete Automation. On your iPhone or iPad, you can also swipe left over the automation and tap Delete.
If you have any third-party apps that are associated with your HomeKit accessories, check for any automations still enabled there as well since that could also be the cause of this behavior.
If this continues and all these automations are deleted from the Home app and third-party apps, then Apple Support would be the best equipped to investigate this issue further. Reach out here: Contact - Official Apple Support
Cheers!