Wow, so much issues on Mate 10 Pro...
The issues I had was apps going crazy after:
Using phone clone to transfer from Samsung device(there were some Samsung app framework got transfered too)
Installing a 3rd party launcher Nova + sesame + tesla unread which screwed up my Theme store and stock widgets
Facebook + messenger(uninstalled them) which keeps interfering with youtube.
Changing screen resolution to HD and this made the phone fonts and icons go haywire.
I made a clean factory reset and refuse to use built in Facebook /messenger or any 3rd party launchers and things are working great for now.
Notifications are working just fine.
Earlier I got the Remax Bluetooth earbuds and yes the sound was sometimes distorted because it doesn't support Aptx codex.
So I got myself Huawei AM60 about few weeks back and no issues since then. Never had drop in sound etc.
Oreo 8 is just like JB before kitkat and Lollipop before Marshmallow when it was first released, a lot Google play apps could not get used to it until several updates, and finally a new version released.