i never had a notification sound when downloading a file/picture in a browser such as Chrome until Android 8 Oreo. I would like this sound silent but i cannot figure out how. is there a setting to disable this sound without putting the phone on vibrate?
Settings > Apps & notifications > Notifications
Find Chrome or any other app you want to configure in the list, tap and adjust the preferences.
I've set the default tone to something more subtle (Titan) in
Settings > Sound v Advanced > Default notification sound
and set the SMS and mail tones to louder ones, while sorting out the endless options in other apps.