I have been a longtime (if not consistent) Mp3Tag user and give kudos and thanks. So, first off I have put “wrong” in quotes because perhaps this is by design and I don’t fully understand. It could be that every single other program and coding library is wrong, and MP3Tag is right….I don’t know, b…

I've written a separate topic on the current state of iTunes/QuickTime and Nero metadata for MP4/M4A/M4B in Mp3tag, with the intention to answer all questions and shed some light into the issues described in this topic: [image] MP4/M4A/M4B: iTunes/QuickTime and Nero metadata …

[image] bengalih: In fact every other tool (from Explorer, ffmpeg, mutagen (python), AtomicParsley, Picard, etc) will see this new “Set from Explorer” name, but MP3Tag will not Where are you looking to “see” this data? If you are using the library feature and make tag edits outside of mp3tag …

I am looking at the Tag Panel (left side) when the file is selected, and also in the Extended tags by right-clicking and choosing Extended Tags. I am literally closing and re-opening MP3Tag in between every attempt at changing data, so there is no issue with refreshing tags.

[image] bengalih: so there is no issue with refreshing tags. There is if the modifying programs do not also update the “modified” date and MP3tag has the library switched on. Did you press Ctrl-T to re-read the tags? [image] bengalih: I am looking at the Tag Panel (left side) The tag…

Alright since you didn’t post a screenshot or confirm if you had refreshed the offending file’s tags, let’s try this. Under File>Options>Library can you confirm if the checkbox beside “Library” is checked in your setup? A picture is worth a thousand words. Especially for the Extended Tags informati…

I would need to refresh tags even if MP3Tag was closed entirely, and then reopened in between each attempt at checking? But yes, I have verified that Ctrl-T does not change anything. I have put up a whole video for you guys to see exactly the issue I am seeing. I think you wil agree it isn’t an i…

I posted a video above, however I didn’t respond that I refreshed the tags with Ctrl+T, because I stated I was closing and reopening Mp3Tag completely. Does that not have the same effect or is there an actual cache? I’ve never seen an issue before where new tags were not loaded on a restart in 15+…

I cannot reproduce the issue. I used an m4a file, set a new TITLE in MP3tag which was displayed accurately in Windows Explorer. I then added a single character in the Windows Explorer Properties for TITLE, saved the change and pressed F5 in MP3tag which now also showed the added character. I don’…

I’ve done some more testing and it appears you are right, M4A files are not affected. It is only M4B files, and it appears only M4B files that actually have chapters.

[image] bengalih: M4B files that actually have chapters. See here on chapters in m4b files: [image] Chapters in .m4b Support I'm editing the Chapters/Menus of several .m4b files. Here is my Problem: No matter what Program I use to add/delete Chapters, …

So I’ve done a lot more testing. I don’t think the post you referenced is entirely relevant since that issue was around the chapter managment itself, not just changing a tag as simple as “title”. However three may be relvance between them. There definitely looks like complications due to the MB4 …

Mp3tag showing “wrong” metadata on M4B files

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ohrenkino August 6, 2025, 7:08pm 11

See here on chapters in m4b files: