It is probably being turned down remotely by the NSA guy monitoring your phone as you may be overpowering his head set.
My wife asks me why I carry my gun around the house. I said I fear the NSA. She laughed, I laughed, my phone laughed. I shot my phone.
My insider source at AT&T told me the S7 Active will get Android 7.0x on May 17th, but it could be earlier and maybe even delayed until past that date.
The Samsung cover has two small protruding nubs that lock into those indentations on the back of the 10.5. This keeps the cover firmly locked to the Tab S.
Chances are, when the NSA hacked into your phone, they added a program to insure that connection to your calls for monitoring purposes is not lost when connected to bluetooth. On second thought, it could be aliens. Yeah, that's more likely, it's aliens for sure.
Mine is a wifi version, bought new in 2014. Transition to 6.0.1 was seamless. Device suffers no lag or degraded performance issues. After 23 months the battery is not as good as when new, but still provides adequate use, every day.