I just bought the Galaxy Note 9 2 month ago. And after receiving the android Q update i can see battery backup is drastically reduced. I'm getting only 3 hours to 3.5 hours of Screen of time with very light usages. Just watching some offline video in Mx player and listening music and watching YouTube and surfing Internet.
i have written multiple feedbacks with all in vain. no update at all from samsung. they say nothing found in logs. so easy. although I am using galaxy active 2 always synced with bluetooth, but sot has drastically reduced. and mostly the standby time.