blackview_admin wrote:1. The app will not automatically be started, you can receive the notification if you do not clean the background. You can add the app in [White List], then you can receive notification after you cleaned the background.
2. There no Battery app on the phone because of the design of Android 8.1.
3. 5GH WLAN is not strong while there is a war penetration, it is better without wall penetration
For the first issue I have already checked the following configuration :
- White List Auto clean : DISABLED

- For one of the APP that is not started automatically, i.e. Outlook
App data usage Background data : ENABLED
Battery optimization is set as in this way 
If you want to check this issue just install one the APP that I have listed and verify yourself.
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For the second issue : there is no possibility to know which APPlication is "eating too fast" the battery. AccuBattery APP give us ALL of these information.

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For the third issue, the check has been done at
one meter from the Router, the signal is unstable (goes away for 5 to many seconds, then it comes back ...) ; with same router using other devices I have no problem.
See the video here https://mega.nz/#!CJpWnC4B!lVycQgjrCypR4gu0LeQWCf-dI3mM_iKffEOA41eDGNI