i have a unlikely issue with my DX50, V1.2.8:
Since a few days my DX50 stucks sometimes (sporadic) during bootup (not more than once per day). It stays forever at the "iBasso Audio Digital Audio Player" screen. A long press of the power button shuts down the device, then it immediatly comes up again to the stuck boot screen. Even ejecting the micro sd will not solve the problem.
Only going into the recovery mode, factory reset and format... will bring the device back to its normal state.
Then i am able to hear music for hours - up to the next device boot.
I did change two things in my setup during the last week:
1. i changed my music-db from mp3 to ogg/vorbis (about 9000 files).
2. i changed my sd card to a sandisc extreme 64GB.
Currently i am trying to isolate if this problem is related to the card/audioformat/hw, but because of it's sporadic behaviour this could take a while.
I could not see any similar postings in this thread (but it is a long thread, so maybe i've overseen it

) - did i hit a known issue? Maybe i've been the first one using ogg/vorbis? :/