Right so I had manged to install /e/ Foundation and everything seemed fine and dandy, until the moment I tried to call with my “new” sweet phone and then it happened; “scuuuuzzishd” it said in the speaker… 
The sound is really distorted and extremely bad both for the caller and the received of the call. None of the parties can hear what is being said. I then started to test and weirdly it seems to work fine when you call a landline where the sound is fine, but then you call cellphones it gets really ugly. You can’t hear a thing…
After some more testing I quickly narrowed down the issue to that it was the Bluetooth that is buggy. I use a professional call center/office headset from Jabra in my office: https://shorturl.gg/jabra-pro which connects the headsets base central throughBluetooth to the phone. This is something that is crucial for me that it works flawlessly in my work so it has to work or i cant use it which is why I been forced to reinstall the Original Samsung OS ROM back to the phone, (and now its working again). Now with that said, once I turned off the Bluetooth calls to landlines and cell phones works great. but when I turn it on and use my headset it is impossible to call because the Bluetooth is so unstable and buggy.
It’s a real shame, I really liked /e/ Foundation and would love to use it, but because of the above mentioned I had to revert back to the Samsung OS.
I understand that this might not be an issue for everyone who doesn’t need the Bluetooth, but for those that do its simply not usable. I hope this bug might get fixed in the future of /e/ Foundation.
I seem to not be the only one with this issue. There is several reports of this exact same issue on different phone models: https://community.e.foundation/search?q=noise where the Bluetooth is really buggy and makes this terrible white noise. 
So it can’t just be my phone model, it’s a deeper issue/bug with /e/ Foundation with Bluetooth. 
But until then I’d stick with the Samsung Stock ROM unwillingly.
Kind regards
PowerQuest
