MALUS gives you

My.Fair.Lady.1964.2160p.UHD.BluRay.H265-MALUS

Video (Untouched) : 60.7 Mb/s
Audio             : English Dolby TrueHD 7.1 @ 6346 kbit
Subtitles         : English, English SDH, Danish, German, Spanish, French,
Italian, Japanese, Korean, Dutch, Norwegian, Finnish,
Swedish

Movie Size        : 84301 MB
Movie Length      : 2h 53m

IMDB Link         : https://www.imdb.com/title/tt0058385

Format            : Dolby Vision, Version 1.0, Profile 7.6, dvhe.07.06,
BL+EL+RPU, Blu-ray compatible / SMPTE ST 2086,
Version HDR10, HDR10 compatible

Notes:

The highest quality audio track is this:
English/Dolby TrueHD Audio/7.1/96 kHz/6346 kbps/16-bit(AC3 Embedded:5.1/48 kHz/640 kbps/DN -31dB)

Note that the TrueHD is 96 kHz sample rate, while the embedded AC3 track is
48 kHz sample rate. MPC-HC player doesn't seem to like that. When one selects
the AC3 audio, it plays at double the speed.

Other players like VLC, MPV and SMPlayer doesn't do that. In those players there
is no difference if one chooses the TrueHD or the AC3 track. We conclude that
this must be some issue with MPC-HC.

We have muxed the files as is, and other players don't have the same "problem".