If you produce your podcasts with Apple GarageBand, you probably have run into a strange issue – at least, if you are creating enhanced podcasts with chapters and links, as it is possible with the sophisticated AAC format.
Sometimes, the carefully selected hyperlinks are just missing in the exported file. The little clickable label that should be overlaying the cover art is not to be found. This is more than frustrating, since it cancelled out the whole post production effort, at least partially.
This annoying bug seemed to appear and disappear with every GarageBand update. I cannot recollect when I saw it for the first time, but with recent versions, things got worse. I almost never got my hyperlinks working the way they were supposed to.
Subchapters are the probable cause
The problem seems to occur with subchapters, i.e. with markers, which have no title and are therefore not a separate chapter, but change the URL and/or the picture within the current chapter.
I noticed that podcast episodes where there are no empty chapter titles usually work fine.
To make a long story short: if you struggle with that issue, try to avoid sub-chapters!
If you have any insights on this bug or any different hints, please let me know via comment form!