I found a trick by myself. The problem is that the notification channel on android oreo reguarding an application "prevails" on the settings within the application itself, in this case whatsapp. If we want, as in my case, to receive notifications of a new message only in the notification bar (without pop-up on the screen) and without sound, it will not be enough to adjust the settings only within the application, but we will have to do it in the new "notification channels" introduced with oreo. However, there is one however, if we set the notification when a new message arrives on "low" (without sound and without visual interruption) at the next message, Oreo will change "by itself" this setting on high , with sound and pop-up screen. Even within the application itself the settings will be changed with the sound on, while those regarding the pop-up notification will remain the same, although the pop-up will be displayed theanyway. The only way to prevent Oreo from overwriting and shaking our settings is this: 1) Adjust the desired settings within the application (no sound, vibration on, NO pop-up) then go to the notification channel of whatsapp and set the importance of the message received on "high", then click on it and change the ringtone to "none". In this way we will to not receive the pop-up on screen notification and settings will be respected. It seems to work, although this morning the urgency of the notification was back on "urgent". Again changed, and seems to be back to normal now. Let me know your experience about that.
