IDE is not using the configured browser to Run/Open HTML file

Problem

1. Create a project and new HTML file
2. Go to Settings | Tools | Web Browser and Preview, only select a non-system-default browser, and change the Default Browser option to "First listed".
3. Back to the HTML file, and Edit Configuration
4. Create a new Run Configuration - JavaScript Debug, set as below
5. Click "Run"
6. The page was not opened in Safari as configured in the Run Configuration and Settings | Tools | Web Browsers and Preview, but the page is opened in Chrome.

Cause

Debugging is only supported in Chrome and browsers of the Chrome family, as stated in the help. So, when you start the app with the run/debug action, the IDE will try to open Chrome (or, if it can't be found in the list of browsers in Preferences | Tools | Web Browsers and Preview, the first listed Chromium-based browser will be used). Also, it won't allow you to select any non-Chrome browser in the run configuration (as this won't work anyway) unless none of the Chromium-based browsers are enabled in settings.

Resolution

If you don't need to debug your application and would just like to preview your page in Safari/Firefox, try using the browser bar in the upper right corner of the editor to open the page in the browser of your choice.