http://www.techradar.com/news/samsung-galaxy-s9-might-not-be-as-advanced-as-youd-hoped

The home button on the display of the Samsung Galaxy S8 makes one thing very clear: the company had fallen just shy of implementing a futuristic fingerprint sensor under the glass. 

Unfortunately, the latest word from the rumor mill suggests that we won’t see the innovation in the Samsung Galaxy S9, either. But there appears to be a silver lining in this development that, at the very least, Samsung is adjusting the location of the sensor, according to TechnoCodex. Chances are good that it will be placed in the middle, as we’ve seen on the LG V30 and Google Pixel 2, to name a few other smartphones.