It seems a known issue. If you check extension log, you will see error like below:
The root reason is that Azure Cli 2.0 could not generate sas token contain table.
Please refer to this issue on Github.
A solution to solve this:
You could use Azure Power Shell to generate sas token.
$resourceGroup = "shuicli"
$storageAccountName = "shuiclidiag630"
$storageAccount = Get-AzureRmStorageAccount -ResourceGroupName $resourceGroup -Name $storageAccountName
$ctx = $storageAccount.Context
$accountSAS = New-AzureStorageAccountSASToken -Service Blob,File,Table,Queue -ResourceType Service,Container,Object -Permission "racwdlup" -Context $ctx
my_diagnostic_storage_account_sastoken= to sastoken.
I test in my lab, it works for me.