Deleted iCloud Mail rules are still applied

For a long time I had active rules that ensured that certain emails were moved to a certain folder as soon as a case predefined in the rule occurred.

I decided to delete all rules on iCloud.com in the built-in Mail program. Just to make it clear, I am not running the Mail.app on my Mac.

Now the error occurs that these rules are still active, although they have already been deleted.