I have the 1811 ASDK installed.

Your steps for recovering a storage account are incorrect in the Azure Stack Operator How-to-guides>Manage Azure Stack> Manage Capacity> Manage Storage Capacity

First: The Set Retention period steps should be in front of the recover storage account steps. As once you run the steps your deleted storage account is immediately unrecoverable.

Second: The process should be as follows
1: Navigate to All Services > Storage
2: Select Storage Accounts > Search for the Account Name
3: Select the deleted account and then select Recover

I read the Gotcha section below your steps but i believe this is the most efficient way to document the process.