Thanks for letting me know! Since the demo, I've moved the game to the in-development next version of the engine, which totally replaces the controls API. I'd like to get a new version of this little demo out with those fixes, there's just some complications with the engine's releases and the build pipeline I use, it's a little boring to get into details haha.
Anyway, one thing you can try is to go into Pause - Settings - Control Options, and disable the right stick aiming. Then go to Settings - Gameplay Options, and set the "aim style" to Pivot.
This means while aiming, you should get locked in place, and the left stick will spin you around to aim. That MAY fix the issue. If not, unfortunately, you'll probably have to wait until I can release the next version.