Often it’s not a matter of hardware. Most software just decodes the lossy core of the DTSMA track, but if you have something special that may be trying to decode the lossless file, it could be making a mess of it. Which is why I asked you to see if an AC3 track synced OK. The 93 English AC3 track is within a few milliseconds of in sync with the 5.1 DTS-MA track. If the decoder isn’t the problem, they should have the exact same sync issues.
Just tested on a laptop with headphones in VLC. Both the 5.1 and 1993 2.0 track seem equally out of sync (audio lagging behind video). The scenes I’m looking at are the beginning of the crawl, when Leia unfreezes Han, and when Vader talks with Luke in the Endor hallway after he turns himself in.
For sanity, I verified the MKV checksum. Is anyone seeing this sync issue?