@Chris Parr Welcome to Microsoft Q&A Forum, Thank you for posting your query here!
This article lists some common problems related to Azure file shares and provides potential causes and workarounds. Troubleshoot Azure file shares performance issues
Based on your scenario, we need to investigate closely I would recommend you to contact support, so If you have a support plan, I request you file a support ticket, else please do let us know, we will try and help you get a one-time free technical support. In this case, could you send an email to AzCommunity[at]Microsoft[dot]com referencing this thread as well as your subscription ID. Please mention "ATTN subm" in the subject field. Thank you for your cooperation on this matter and look forward to your reply.
Please let us know if you have any further queries. I’m happy to assist you further.
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@Chris Parr Just checking in to see if the above answer helped. If this answers your query, do click "Accept the answer” for the same, which might be beneficial to other community members reading this thread. And, if you have any further query do let us know.
