Voice Memo won't play
I've arrived at the old problem of a corrupt voice memo, which was common enough a decade ago, and as it appears, Apple still hasn't resolved the issue.
I can see the recording in the list of files on my phone, which shows its duration (1hr 36mins), its format (m4a), and its size (22.5mb - looks like it is about half the size it should be even for a compressed m4a thing). The file, however, does not play. If I press play, it remains at 0:00, and pauses after a second. If I drag it, say to 22mins in, it remains there, and does not play.
Thinking that I could sort it on my Mac, I airdropped the file to my desktop, and also used a file-handling software to go to the iphone disc and copy the original file (named with a string of numbers) to my Mac. Neither of these files play (on iTunes, QuickTime player, VLC, or Vox).
The phone memory doesn't seem to contain any other sound files amongst the voice-memo recordings, fragmentary or otherwise, as none appear even when I ask my file-hangling software to show all files including system ones.
I am on iOS 12.1.4 (software up to date), on a relatively new iphone. I haven't had problems with previous recordings, even longer ones on this phone so far.
Does anyone have ideas about how to sort out this issue?
iPhone X, iOS 12