If each time you click a Help button in a block dialog you get the same Help content regardless of which block you are in, you might be encountering an issue with cached information not getting updated properly. To resolve this:

Navigate to the AppData folder at c:\Users\username\AppData\Local\QTProject\Assistant.

Delete the entire Assistant folder that contains cached information.

Relaunch ExtendSim. The Assistant folder will be recreated in AppData as an empty folder. At this point, your Help system should be working better.