How long until Construct 2 detects a new game version? The description of offline games and the browser object doesn't really explain how long it takes for Construct 2 to detect a new game version and to begin downloading it.
It's a cache problem maybe ? If you are running your game on a browser try to ctrl+F5 on the page, the cache will be deleted and you should see the new version.
Develop games in your browser. Powerful, performant & highly capable.
....why are so many people giving irrelevant answers to my questions?
Because your questions are unclear ?
Well have fun with this "problem".
It's not a problem? It's a question?
It should begin once the game has completed loading the current version automatically in the background. You can check the status of updates using the browser plugin (just set a text box to that value if you want to see it).
Construct 2 doesn't detect it, the browser does. For example open the browser console in Chrome (ctrl+shift+J) and you'll see status updates as it checks for an update and downloads one if it is found.