Are you downloading audio from YouTube by any chance? Basically there’s this common problem with most youtube downloader websites where they give you a file that says mp3 in the file name but its actually an m4a (an mp4) so it confuses iOS’s or Android’s built-in audio player (koala tries to detect this problem specifically because of these youtube downloader sites, but it can’t always get it right because its difficult to detect)
All you need to do is change the filename like “some-song.mp3” to “some-song.m4a” and it will work.
I have spent a while trying to fix this problem but ultimately its a bug introduced by these shady youtube downloader sites and to fix it would take me ages. I want to do it because a lot of people have this problem but there are other more pressing things right now, hope that’s understandable!
WARNING: Downloading audio from YouTube and using it in your song is potentially a copyright infringement. Koala Sampler/elf audio/mazbox ltd do not endorse doing this and recommend seeking permission from the copyright owners!