after after running

pulumi up

successfully, subsequent runs are producing this error:

~   ├─ aws:rds:Cluster              rds-cluster-patient-access-prod  **updating failed**     [diff: ~availabilityZones]; 1 error
     ├─ aws:autoscaling:Group        app-services                     **failed**              1 error
     └─ aws:autoscaling:Group        edge-services                    **failed**              1 error

Diagnostics:
  aws:autoscaling:Group (app-services):
    error: transport is closing

  aws:autoscaling:Group (edge-services):
    error: transport is closing

  aws:rds:Cluster (rds-cluster-patient-access-prod):
    error: transport is closing

  pulumi:pulumi:Stack (aws-prod):
    error: update failed

    panic: fatal: An assertion has failed: Expected diff to not require deletion or replacement during Update of urn:pulumi:prod::aws::aws:rds/cluster:Cluster::rds-cluster-patient-access-prod

I'm not making any changes to the cluster or related resources (availability zones, auto scaling groups).. any ideas?