Intermittent Azure Function upload failures for files larger than 30MB
We have an application where users sign in via Azure AD B2C and use an HTML frontend to upload/download files. The frontend calls an Azure Function that handles file operations against Azure Blob Storage. In production, the function uses DefaultAzureCredential, as it has been assigned the Storage Blob Data Contributor role.
We're seeing inconsistent behavior when uploading larger files (typically around 30 MB). Sometimes the upload succeeds, and sometimes it fails for files that are greater than 30MB. Smaller files generally work without issue. What's also confusing to me is that when we run the function locally in VS Code and test through Postman, we can successfully upload files up to 100 MB.
We're trying to understand what might be causing the failures in production. Are there any Azure Function settings, request size limits, timeout configurations, authentication considerations, or other Azure services in the request path that we should be looking at? Thanks in advance!