Hello Mark,
I have replicated the same issue as yourself. You will need to delete the Azure Policy assignment first, before you can delete the initiatives. An Azure Policy initiative can contain one or more Policies.
- Go into the Azure Policy dashboard
- Go to 'Assignments'
- Change the scope where the initiatives are assigned e.g "Decommissioned" or "Sandbox".
- You should now see the Azure Policy initiative (e.g Enforce ALZ Sandbox Guardrails)
- Click the three dots on the right and "Delete assignment"
This should now delete the assignment, note this can take up to 30 minutes take effect.
Now go into the Policy Definitions and you will be able to delete the policy initiatives by locating the initiative, click the three dots on the far right and then "delete definition"
I hope this helps you, please let us know if this helped
Thanks