I've built and tested my add-in using Fabric React. When I sideload it from localhost:3000, everything works fine. I then created an Azure app services website to host it. Updated the manifest XML file to point to the correct URL instead of localhost:3000. I updated all references from Office.initialize to Office.onReady(). Still, every time I sideload the app from the Azure manifest I get the following error:
Office.js has not fully loaded. Your app must call "Office.onReady()" as part of its loading sequence (or set the "Office.initialize" function). If your app has this functionality, try reloading this page.
Any ideas as to why this happens?