Hello Jay McDonald,
I'm glad that you were able to resolve your issue and thank you for posting your solution so that others experiencing the same thing can easily reference this!
Since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others ", I'll repost your solution in case you'd like to "Accept " the answer. Accepted answers show up at the top, resulting in improved discoverability for others.
Issue: Azure File Shares - Identity Based Access API Error
Error Message: Failed to update storage account
Solution:
Customer resolved this doing the below:
Sina's reply helped with step 1 - I decided to recreate the link between my storage account on AD & the storage account by deleting the original account created and recreating it.
I don't believe this solved it but every step helps - I tried again but got the same error.
I tried enabling this through alternative methods again - https://learn.microsoft.com/en-us/azure/storage/files/storage-files-identity-assign-share-level-permissions?tabs=azure-cli
This failed with no error message in either Powershell or Azure CLI but kept giving me the same error when trying on the portal.
Doing some googling I found a similar issue someone had with their API on key vaults. This recommended running az upgrade in Azure CLI - I ran this and tried adding permissions again through Azure CLI and this worked. Bit of a strange one so hopefully this helps anyone else getting similar errors in future.
I hope this is helpful! Do not hesitate to let me know if you have any other questions.
Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful.