I can confirm that after last update the issue is gone.
Its now been 24 hours with fingerprint unlock enabled and no restarts!
The latest update i recived was the April security patch update. I will update if issue reoccurs, lets hope Samsung has done something about it though and this isnt a random glitch.
To all who see this, I also had this same issue. And I fixed it in just less than an hour.
The fingerprint scanner on the Note9's and S9's do seen to not like moisture. I powered my Note9 off, and rested it on it's screen on a flat surface.
I then took 99% rubbing alcohol and a Q-Tip and poured drip-sized amounts of alchohol on the Fingerprint sensor. I wanted to make sure the fingerprint sensor was neatly dressed in the alchohol and allow the alchohol to dry there.
Waited about 15 to 20 minutes and then powered the phone on. Set the fingerprint scanner to unlock the phone, and tested this 3 days before posting here. I no longer get random reboots.
If you try this yourself, make sure you use 99% alchohol. 70% has water mixed in which the sensor may clearly not like if the issue is really moisture getting in the sensor.
I tried this after seeing another user in another forum claim that he used rice to fix his sensor rebooting issue. Rice works but it takes longer.
Do this at your own risk. Good luck.
My S9 plus is doing the same thing. I stopped it for a long time with leaving up my always on display but yesterday it started doing it regardless of that being on. So now if fingerprint unlock is on then it cuts off going idle. Can I get a real fix?
Has anyone truly solved this problem?
I've been having this issue forever, and I would really like to be able to use my fingerprint sensor again.
Samsung has been no help. When I call the customer line, they tell me that this is not an issue that they're aware of, and redirect me to get it serviced.
I have the same problem with a Note 9. It started two nights ago. There’s no solution for this, just disable the fingerprint unlock, Samsung is doing nothing about it.
I solved this problem by disabling fingerprint security to unlock the phone. Just in case someone is having the same issue. I spent a lot of life energy with all of the resets and restarts when it is as simple as disbling fingerprint phone unlock. I am hoping Samsung will fix the problem undoubtedly created by one of the 7 mandatory System updates of the last year... JUst the fact that these System updates are mandatory and not optional will have a significant impact on my decision to buy another Samsung when I upgrade. It is nothing short of corrupt ... Microsoft does the same thing, so maybe I just need to shut up and take it ...
I know this is an old thread, but adding my woes to it. My s9+ just started doing this on 5/2/20. First time, clearing the cache fixed it, then it started happening again exactly 3 weeks later. Factory reset seemed to fix it, now it is 4 days later and the rebooting started again. I finally gave up and disabled the fingerprint unlock an hour or so ago, hopefully that will end my problems.
Can confirm, the fingerprint sensor still works for logging in to the apps that I sign in to with a fingerprint, even with the feature disabled for unlocking the phone.
Yep just started having this same issue too on my Note 9. Tried everything up to factory reset.
Nothing fixes it except disabling fingerprint unlock.
Samsung please fix this.
So crazy. My phone just started doing this also. I just made my last installment loan last week just before it started so I was thinking it was just a conspiracy to make me buy a new phone. Always seems to work out that way with all the updates they send. Sorry for the trouble but at least relieved I am not the only one. I have lost my mind this last week constantly resetting, safe mode, wipe cache. Absolutely ridiculous. Thanks to this complaint center, I disabled my fingerprint sensor (which I have used for 2 years now) and so far it has not rebooted. Of course it has only been 20 minutes but that is much better than it has been. Thanks for the help. Why can't this be Apple's problem? I hate Apple but doesn't ever seem like they have these issues.
I can confirm that after replacing the fingerprint scanner that the problem went away it was about $20 in parts if you are handy and can fix it yourself and if your phone is out of warranty.