Not to dig up an old thread, but curious as to if you get delayed notifications with it on? I'm having an issue where push notifications are not coming through until I wake up the phone. When I wake up the phone first thing in the morning I'm getting bombarded with notifications that should have come through during the night and I can't figure out why it's doing that. Same apps on my Pixel 3 and no push notifications issues with that phone.
I have adaptive battery off and "put unused apps to sleep" is off as well. Saw this setting and wondered if it would solve the issue.