When you attempt to create a Bimodal Consumption Design for VM Apps and All Apps workloads using shared workloads within a single vSphere Cluster, adding a cloud account fails if the All Apps organization is already configured with the same vSphere Cluster.
VCF Automation 9.1
This behavior occurs because of the architectural sequence constraints required when sharing a infrastructure pair.
The Mixed Tenancy feature is specifically designed to support a migration path where you have an existing VM Apps organization and want to gradually migrate it to an All Apps organization sharing the same vCenter and NSX Local Manager infrastructure.
Because of this intended migration direction, when two organizations share a vCenter and NSX Local Manager pair, the VM Apps organization must be created and fully configured first (including mapping the cloud accounts) before the All Apps organization is configured against the same infrastructure. Attempting the reverse deployment sequence is unsupported.
This issue is currently under review by VMware Aria Automation Engineering. Subscribe to this knowledge article to get updates on this issue.