having a similar issue with recreating a deleted storage account (i delete the whole RG and recreate it to test..).. this was the run I made to pick up on the previous pulumi up which failed due to the subnet saying "another operation in progress":

Updating (modular):
     Type                                    Name                Status                  Info
     pulumi:pulumi:Stack                     modularity-modular  **failed**              1 error
 +   ├─ azure-native:network:Subnet          sz2-n11024          created
 +   └─ azure-native:storage:StorageAccount  n11024storage01     **creating failed**     1 error

Diagnostics:
  azure-native:storage:StorageAccount (n11024storage01):
    error: autorest/azure: Service returned an error. Status=404 Code="StorageAccountNotFound" Message="The storage account n11024storage01 was not found."

and then running it again (just a new pulumi up, no changes):

Updating (modular):
     Type                                    Name                Status
     pulumi:pulumi:Stack                     modularity-modular
 +   ├─ azure-native:storage:StorageAccount  n11024storage01     created
 +   └─ azure-native:storage:BlobContainer   pulumi-state        created

Resources:
    + 2 created
    11 unchanged