Eventually, after two weeks, Samsung Customer Service replaced my Phone with a new one.i would like to Describe my Experience with the new Phone.
Now I have New Galaxy A51; my Phone has Android 10Q with Build Number A515FXXU1ASKJ. My previous GALAXY A51 had updated to A515FXXU1ASL6 that had a lot of problems with Bluetooth and WiFi.Because of my experience, I stopped updating the software on the new Phone. The Phone works perfectly without any problem. Bluetooth works without stuttering and keeps connection always.WiFi works perfectly, and the Phone never freezes or lagging. But my memory usage is unusual; in the last 24 hours, my average usage of memory is 3.5GB (60% of 5.8 GB available memory). You can see in this picture; six applications get around 2.4GB of memory in one day.
I think GALAXY A51 problems occur in new Build Numbers (A515FXXU1ASL6 / A515FXXU1ATA4). Thus, please do not update your Phone until Samsung solves problems in new versions. Please, anybody, have Bluetooth issues; please write your 'Build Number' in comments.
For finding your 'Build Number', you should go to the address below:
Setting > About Phone > Software Information > Build Number
This is because the ram is being used to this level due to the system. It will help the phone perform smoother as the system has loads of ram to work with. Unused ram is not going to be useful, so it might as well be used. If you are worried by the ram management, when you start to open many large ram apps, the system will use less ram to make room for those apps. So having 1gb or 2gb of ram free when the phone is idle is not a bad thing; it is actually good as you know it has been optimised to run the system well when it can and is not wasting unused ram on nothing.
Only fix to fix BT audio sluttering is to downgrade firmware to original December 2019 firmware > A515FXXU1ASKJ A515FOXM1ASKJ
And than disable update and update notification.
I did it on my A51 and now I can 100% confirm that BT audio works without any problems.
That is the only fix until Samsung is going to release offical fix for SL6 update.
This was the last time I bought SAMSUNG's any product. After this I am shifting to Huawei and RECOMMEND everyone to do the same. I have lost the trust from SAMSUNG after purchasing A51. It started to give me issues within 1 hour of opening it and taking it out from the box.
iT JUST DOESN'T CONNECT EASILY WITH ANY BLUETOOTH DEVICE, YOU HAVE TO RESTART THE PHONE IN ORDER TO CONNECT IT WITH THE CAR OR ANY SPEAKERS.
Last night I was driving and the map was on and I was on call with my family when suddenly the phone restarted itself out of nowhere. SAMSUNG YOU TOOK ALL YOUR TRUST AWAY AND THE BEST PART IS YOUR SERVICE CENTER WAS SAYING THEY WILL REPAIR THE CELL PHONE AND WILL TAKE 2-3 DAYS TO DO THAT.