I cannot figure out what was the reason behind the problem, a mysterious case indeed. I have forwarded the issue to the Engineer for testing.
For the meantime, if you have a spare TF card, please try the following:
(1) format the card in N5, copy the DSD128 files and the V3.0 firmware to the card
(2) Refresh v3.0 firmware again
(3) try to play the DSD128 file in the TF card immediately, without update music library, with and without headphone plugged in.
Fortunately you can continue to enjoy your music right now, I have a weak heart, especially with the numerous instants recently, have to take a break later .....
Yes, I'll have my Chinese New Year break very soon, has started my holiday countdown already.