DevTestLabs provisioningState failed

Hello,
I couldn't change anything in my DevTest Lab, because the provisioningState since my last change is failed.

How do I change the provisioningState ?

Reproduction steps:

We have a policy which requires Tag-Names on Resources.

If I go to "Lab settings" and change "Default resource group allocation" to "All virtual machines in one resource group" I get the error:

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Failed to save the lab settings. Error: {"error":{"code":"AppendPoliciesFieldsExist","message":"Policies attempted to append some fields which already exist in the request with different values. Fields: 'tags[BudgetName]'. Policy identifiers:'[{"policyAssignment":{"name":"Add budget name tags to subscription and resource group","id":"/providers/Microsoft.Management/managementGroups/mg-kx/providers/Microsoft.Authorization/policyAssignments/rxsz84jnhf2vco30q6dbku19"},"policyDefinition":{"name":"Add tag for budget name on Resource Group","id":"/providers/Microsoft.Management/managementGroups/mg-kx/providers/Microsoft.Authorization/policyDefinitions/a66c0a5b-b928-4881-b7ca-0ceaf9410ce2","version":"1.0.0"},"policySetDefinition":{"name":"Add budget name tags to subscription and resource group","id":"/providers/Microsoft.Management/managementGroups/mg-kx/providers/Microsoft.Authorization/policySetDefinitions/32c6c1e0-5796-4024-b14a-1bc4ab8c1a15","version":"1.0.0"},"policyDefinitionReferenceId":"Add tag for budget name on Resource Group"}]'. Please contact the subscription administrator to update the policies."}}

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This error is ok, but because the deployment failed, the DevTest Lab is now in provisioningState=Failed.

If I try to undo the setting, I get:

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Failed to save the lab settings. Error: {"error":{"code":"ResourceIsNotInValidState","message":"Resource 'shuttlelab6' is not in a valid state 'Failed' for operation 'PUT'."}}

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What must I do to get out of the "Failed" state?

Thanks