It's a network error, if you check your storage account logs with

StorageBlobLogs
| where UserAgentHeader contains 'azsdk-java-azure-storage-file-datal'

You will see

StatusCode 403
StatusText IpAuthorizationError
CallerIpAddress 10.120.*.* // or some private ip not in your allowed vnet list

Seems that the file discovery is not using the ips allocated to the workspace, and even with the Access Connector whitelisted, the result is the same.