Reports last year claimed that the upcoming Samsung Galaxy Note 9 would be the first Samsung device to feature an under-display fingerprint so. That has become extremely unlikely, however, as a new report claims the device will feature a rear-mounted sensor like with the Note 8.
https://www.notebookcheck.net/The-Samsung-Galaxy-Note-9-will-not-feature-an-under-display-fingerprint-sensor.282894.0.html