I have the S8+ for only a few weeks and Im having the same issue. It's frustrating. Seeing as you've had this phone for awhile now, Samsung doesn't seem to be doing much about it Hopefully they fix it soon.
I figured out that trying to use the fingerprint scanner while I have the phone plugged into a quick charger seems to replicate the problem. Also, once it has happened, if I open Samsung pay, it immediately vibrates as if I'd scanned my fingerprint, then gives the error "make sure your finger covers the scanner." But absolutely nothing happens when I then touch the scanner until I reboot.
My galaxy S8 just got an update yesterday, July 4th and it still randomly shuts off the fingerprint sensor.... annoying that I have to lose all my information but I am taking it back to the wireless store? This is unacceptable on a phone a few weeks old. Never dropped. My old iPhone 5s had zero issues.
Personally I'm not quite ready to chuck my phone in the dumpster BUT I have not seen any sign of this issue being taken seriously yet by the monitors.
Can you please create a bug / issue to track this and keep us updated on the planned release for the fix? I'm new to the Samsung issue tracking world but it seems like this is a problem experienced by a lot of customers and I'm not seeing much in the way of urgency from Samsung product management.
I've had to turn off fingerprint scanner gestures and I still occationly have to use my PIN because the sensor is ignored when I'm trying to wake my phone up. PLEASE FIX!
Having the same problem. Just got this phone too.
Perhaps this should have been fixed by now considering all the complaints?
No rush, though. It was only a close to $800 phone that doesn't work properly.
I have had the s8 as soon as it was available. I believe it was a month or so after I got it that it did this once or so. But now I am nearly unable to use the fingerprint scanner at all. It might work 4 times a day, but thats doing constant reboots. It is constantly not registering that my finger is even touching the sensor.
WE NEED A PROPER RESOLUTION TO THIS ISSUE!!! *raises pitchfork*
They know about this issue but refuse to fix it. I saw this in the manual that you can access in Settings. Disabling FPS gestures worked for me for over a month and the dialer code is better for your phone than reboots. Cheers!