My girlfriend recently got the S8 and it would not work with the libre, I have however now got it working, what I did was to downgrade it to firmware version G950FXXU1AQC9, the exact filename I downloaded was G950FXXU1AQC9_G950FOXM1AQC9_BTU.zip I believe you can get it from samfirm.com but I got it from a French site as it was faster, I then flash as shown on this forum topic: forum.xda-developers.com/galaxy-s8/how-to/official-stock-firmware-update-odin-t3598172 and its now working perfect. BEWARE: I had to do a factory reset after flashing so make sure you backup, if you don't do this you will get constant force close errors until you do a reset. Also make sure you disable automatic updates or the problem will come back next time your phone updates. This IS Samsung's fault as none of the third party apps will recognize the libre either but on this downgraded version they ALL work so it must be Samsung's fault.