Wherefore art thou, Bluetooth headset?

Great. After multiple usage so far today, it would appear the aforementioned problems with my Akono headset were not the fault of the headset at all. (Still, mucho kudos to SE for the replacement; at least this helps clear it up.)
It looks like the problem is indeed with my T616. The phone is out of warranty. This is, as the Fontosaurus would say, the suck.