Hey @SuperBisco,
have you tried already to turn the experimental features in the Stadia App on? This might be a try, even if the Galaxy Tab S2 is not supported at the moment, but the Stadia App might still work with it:
If that doesn't help, it might be good if you do also leave this as feedback for the Stadia developers as they read every piece and it might help to see more demand for this device: Please make sure to submit this feedback in the Stadia app by tapping your profile icon in the top-right, then navigating to the "Feedback" section.
Even if I enable the experimental option, no games work.
Stadia runs but every game I run drops back to stadia menu.
Still doesn't work on my Tab S2 on experimental.