There are two that work fine that are cheap for the Note 8 which if you search here you will see are recommended. I have this one below and it works great. No loss of sensitivity. Does pick up fingerprints though.
https://www.amazon.com/gp/product/B074G1W2RC/ref=oh_aui_detailpage_o08_s00?ie=UTF8&psc=1
Couple of my pics.
https://i.imgur.com/HS9dQF4.jpg
https://i.imgur.com/5zHLvwR.jpg
Here is another people recommend.
