Just to add to all of this. I have an s10 plus with the same problem. Whenever a secondary audio device, ie bt device or headset that has media turned on is present, the notification sounds go to that device. They do not come out of my phone, but they do play on the bluetooth.
I tried talking to samsung support through chat, and they were well..to be nice, horrible. They barely understood the pretty simple issue, and once they finally did their answer was to reset the device. I declined to reset.
I then went looking and have found all sorts of issues on other forums describing similar issues. It actually sounds like it may be a "feature" that they added with the newest updates for "privacy". Haven't been able to determine if it is a phone or android thing though.
Anyhow, the lack of support on all of this is a little ridiculous. The issue is obviously present and nobody at Samsung or Google seem to be responding to it.
I really wish someone would stop with the scripted responses and just say that they dont care, they dont plan on fixing the issues, and that we all wasted money on a phone that has no way to notify us unless we walk around all day with a bluetooth stuck in our ear.
Did you get it figured mine was the same but found a setting in the bluetooth section in settings shows your devices and click on the settings icon for bluetooth device and turn the media audio and should go through your phone after worked for me.
No, I've gone through every setting I can find, since the update to Pie, this broke. If you found a way please provide exact steps because there are many of us experiencing this same issue.
I have S9 and found a setting for this on my phone. Go to settings then go to connections and then click on bluetooth. It will show all devices that are connected and on those device listings there is another settings icon click on that and it will show like 3 different options to click on turn off the media audio and should work. That's what I did and it worked for me
This would work if you are only use the bluetooth device only for phone. 90% of the time I have it attached for music or audio book. You can't turn off media in this manner.