This may be a bit of a necro-post but just wanted to offer what i had.
I use the Osmo Mobile 2 with my Samsung Note 8 and it works perfectly fine. I don't see the sample video there anymore, but I use mine to film for my youtube channel and do promo videos.
Things you want to try to ensure that your Osmo Mobile is working properly and producing smoother video:
1. if at all possible ensure that your Phone's image stabilization is disabled. if it isn't, the camera will sometimes get jitter and jerky movement because one stabilizer is fighting another.
2. Make sure your phone is balanced and your gimbal is calibrated. If you have any chords plugged into your device make sure you account for these and that they do not put any excess weight or drag on the phone as it will throw the gimbal off balance and cause it to fight and jerk even when being held still.
3. there are multiple settings (at least on the Osmo Mobile 2) for the speed at which your gimbal makes its changes. in your settings you can select between the two speed modes and you will see a man running or walking depending on the mode, i recommend the walking mode, its a bit slower but your gimbal will be move more smoothly when making adjustments.
4. make sure there is no debris or gunk in the joints of your gimbal. anything adding resistance will cause the gimbal to fight and jitter.
5. Your gimbal can account for an amazing amount of movement, but still try to make your own movements as smooth as you can. practice rolling your feet with your knees bent as you walk, and if you're turning the camera try to use your whole arm.
6. I personally try not to use the joystick for panning unless that is all im doing for a shot. a fixed motorized pan will look great but it will stand out if its in the same clip as a pan using your arm.
I hope this helps.