SUMMARY
Elisa fails to play certain m4a files. VLC and mpv can play it properly, as can Firefox in the browser.
The m4a files were downloads from bilibili.com using yt-dlp, with extra modifications made to the tag metadata using MusicBrainz Picard.

STEPS TO REPRODUCE
1. Download the audio file from https://files[.]williewillus[.]net/adhoc/gouzhiqishi_cantonese.m4a (too large for bugzilla attachments)
2. Put it somewhere under the music directory
3. Rescan the library

OBSERVED RESULT
The tracks do not appear in the library. Navigating to the Files pane and trying to manually play the file there results in a dummy entry with a strikeout glyph being added to the playlist and nothing actually playing.

The log outputs this when the folder containing the file is loaded and when the file is played, respectively:
TagLib: Vorbis::File::read() - Could not find the Vorbis comment header.
qrc:/qt/qml/org/kde/elisa/qml/DataGridView.qml:98: Error: Cannot assign to non-existent property "currentIndex"

EXPECTED RESULT
The file is properly recognized and added to the library, and Elisa can play it properly.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 6.5.2
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Kernel Version: 6.17.7-arch1-1 (64-bit)
Graphics Platform: Wayland

ADDITIONAL INFORMATION