Too Long; Didn't Read
A Practical solution for CORS (Cross-Origin Resource Sharing) issues in IONIC 3 and Cordova. CORS is a method to prevent a client to request a display a service from a host other than the one that is currently showing. This is done for security reasons. Ionic’s blog has an old post on CORS issues. Unfortunately, the solution that they provide is only suitable when you are running the app using ionic serve or ionic run -l. That solution will not work on the production release!