Hey @Sunflower Labs , it's difficult to say what could be causing the issue without more information.
But here are somethings to do in order to diagnose the issue:
- Enable diagnostic logging on your app service. This will help determine what errors you're encountering on your deployed API. Right now, it isn't known where the issue.
- Review troubleshooting guides to better investigate what the issue could be, such as performance or connection related issues.
Furthermore, with a basic workflow such as uploading a file to a SharePoint document list, you may want to consider using a Logic App instead. It would be a simpler setup allowing you to leverage a suite of prebuilt connectors; which SharePoint is one of.