This issue is caused by a malfunction on android Power management on samsung S8
First some links how about it works, and last, how to resolve this issue
This link explain how to android management the power
https://developer.android.com/about/versions/pie/power
This link explain how to android work on doze and standby, its here on S8 restart itself
https://developer.android.com/training/monitoring-device-state/doze-standby
This link explain how wakelock works
https://developer.android.com/reference/android/os/PowerManager.WakeLock
This link explain adb shell dumpsys
https://developer.android.com/studio/command-line/dumpsys
To Resolve this issue is necessary an application with enable wakelock function for you S8 dont enter in doze mode
Because the issue occurred when S8 is on doze mode and enter in a maintenance window
I used termux application on this tutorial, because termux have easy access to this feature for non dev IT dudes
Install termux on playstore
Open termux
In terminal type it termux-wake-lock
#!/bin/sh
if [ $# != 0 ]; then
echo 'usage: termux-wake-lock'
echo 'Acquire the Termux wake lock to prevent the CPU from sleeping.'
exit 1
fi
am startservice \
--user 0 \wa
-a com.termux.service_wake_lock \
com.termux/com.termux.app.TermuxService \
> /dev/null
After this, your S8 will scape doze mode when the display turn off and lock, and dont will restart itself anymore
This is necessary every time your phone reboot or shutdown, unless you have root privilegies, termux-boot or adb shell
There are other ways with adb shell like this https://www.xda-developers.com/stop-wakelocks-android-without-root/
Waiting for samsung resolve this issue, meanwhile ...
[ 07/2020 ] Samsung release another update, but the issue continue
[ 07/2021 ] still