Hey Luis,
What version of Umbraco are you using?
I’ve never used Azure File Shares for this, and I’ve never come across an Azure Web App that does. Blob Storage is definitely the usual choice for this and will solve FCN problems - IF this is what’s causing them.
I question this as I’ve had FCN problems before, but never with media - IME media doesn’t change enough to cause these problems. I’m interested to understand how you came to the conclusion that it’s FCN + media changes specifically that’s causing the restates.