Thank you for your help, that was the first thing I did. Ended up calling and talking to tech support they suggested returning phone and ordering a replacement. So now I am waiting on replacement.
How is this a solution?
The actual solution (as pointed out by others) is to disable the fingerprint reader until Samsung works through the problems with the firmware.
This randomly rebooting started on my phone on a Friday evening after an update.
If after testing your device in safe mode you still experience the symptom, I recommend having your device checked out by a Samsung authorized technician. You may take your device to your local UBreakIfix and they can usually have your device back to you within a day.
I realize this is an older thread, but I just got off the phone with samsung. The tech confirmed that it was a known issue with the fingerprint unlock and they are working on an OTA update to fix it. Took them long enough and hopefully it will fix the problem.
Finally a solution that seems to be working on my phone. I got the fingerprint sensor replaced at a ubreakifix and so far no random reboots. Not sure what was going on with the other sensor, but I'm keeping my fingers crossed that this fixes the problem. Any one else have their sensor replaced? If so, what were the results?
I have a Galaxy Note 9 and I faced the same problem here.
It happened after I've used it for a video recording for a couple of minutes underwater, less then 1m deep. After I dried it, everything was okay until the next day, when the phone started rebooting when kept idle for some minutes.
I followed this steps for troubleshotting and none of them worked:
1. Used the phone in the Safe mode.
2. Reset all the confurations.
3. Wiped the cache.
4. Factory Reset it.
I took it to the support service and they said that it's a main board issue and we have to replace it. But, since it's 4 days out of the warranty period the cost of the repair isn't worth.
Luckly, I've found the post at XDA Forum mentioning that it was problem in the fingerprint sensor regarding moisture. I tested the sensor and it was really failing some tests. After disabling the fingerprint unlock the problem didn't ocurred. So, I cleaned the sensor with the rubbing alchool and left drying. It worked for one day, but the next day I had the problem again and the fingerprint sensor test wasn't acusing any failure. I cleaned it again and left in the rice, and so far it's working fine.
I'm really disappointed with the support service diagnosis.
Yes same issues I had fix it by rebooting the phone into factory menu by holding pwr. Bixby, and vol up when you feel the vibration let go of power button. Select the clear cache portion. And then reboot into the os.