Comment 2 for bug 1973641

This is currently a known limitation with BYO resource groups and destroy controller

https://discourse.charmhub.io/t/juju-2-9-new-azure-features-disk-encryption-byo-vnets-public-ip-constraint/4030

Juju must not delete the resource group, just remove the relevant contents applicable to just the model(s) being removed. We'll need to look into what's needed to remove the current limitation. Until then, you need to manually remove any remaining resources.