User Anthony_Hopkins experienced issues with image uploads on Heroku, where the Uploading… process never ended. Despite verifying a correct Heroku-S3 connection and a successful server response (HTTP Status 200), the problem persisted. After ruling out JS errors and noting that the same configuration worked locally, Anthony_Hopkins explained that Heroku was chosen by the client and the issue was likely client-side. codinghorror and sam suggested potential issues with the Heroku install, recommending a docker-based install. However, Anthony_Hopkins eventually discovered and fixed the issue, which was due to an invalid HTTPS protocol configuration.
Heroku is a server layer. As you see the server response is correct (identical as at my Local machine). File saved to S3 correctly. The problem is client (Browser+JS) side.