Wrong AWS credentials being used

Overview

If you are experiencing AWS authentication errors despite having provided the correct AWS credentials in your project or context environment variables (e.g. AWS_SECRET_ACCESS_KEY, AWS_ACCESS_KEY_ID or other means as documented here, this may be caused by AWS credentials previously set for the project in a legacy settings page.

Solution

If this appears to be the case, in the "Environment Variables" section of your project settings, you should have the option to delete the legacy env vars as shown below:

Once completed you should no longer see AWS authentication issues on your builds.