Why is the correct live page is not selected when I select a string in the editor?
Rigi can do a lot, except sorcery :-)
If you want to see a specific text in your application, you will have to navigate to the right page, perhaps with special permissions such as a password and/or need to simulate an error message. External applications like Rigi do not have that domain knowledge.
Rigi solves this by letting the developers provide that information in the form of HTML Previews. These can be captured by domain experts, or automatically during automated UI tests (i.e. implementation of domain knowledge). Besides this, Rigi also provides live URLs for specific web application types (e.g. PIM and CMS).