Hey there!!! I had a same issue and fingerprint scanner seemed little bit slow as compared to old back of the phone sensors.
but here's the solution it worked for me and can see some improvements. try it out
- Goto settings and search for "optimise battery usage" click on result
- you'll have a list, select second option "optimise battery usage"
- once you're inside optimise battery usage setting you'll see a drop down list. select "All" from that list.
- after that click on search button(top right corner as shownin screenshot) and search for "biometrics".
- you'll find "com.samsung.android.biomatrics " turn that off and you're good to go 👍.
- restart your device once and see if your problem solved or not.
