Putting the apps on the SD card won't run them from the SD card. You have to put a link to them where they were originally. Android looks for them where they installed. (The link makes it look as if the app on the SD card is actually still in internal storage.) Not all apps will work from the SD card, though.
Changing where apps are downloaded to doesn't change where they install to. If you download an app to the SD card and install it, it will still install to internal storage (because the installer installs to internal storage).
Android was designed to use the SD card for data files - pictures, music, documents, videos, etc. It was never designed to run apps from there, and often can't.