Thanks for confirming and showing the screenshot. Since you already left the family group, the most important step now is to refresh the account policy on your device.
Sign out of your Microsoft account in Edge, restart your PC, then sign back in with the same account. This forces Edge to sync your updated status from Microsoft’s servers. If the message still appears, go to Windows Settings, open Accounts, and check that your profile is linked to the same adult Microsoft account shown on the Family Safety page.