Can only sometimes play the audio from Lumix GH1

Yesterday I was looking through a lost project from 7 years ago that was shot on a GH1. I decided to import it into Resolve to try out the auto-syncing feature and wasn't having much success. Eventually I realized that some clips had audio and some didn't.

The clips have audio when playing in File Explorer so it's not the clips at fault.

[Peter Chamberlain]

Are you on W10 with the latest windows update?
viewtopic.php?f=21&t=69837

Yes, I'm on the latest Insider build, version 1803 build 17682.
Since posting this I realized that not all of the footage from the project was shot on the GH1 and the footage that does work was actually 5DMII footage. Seems the issue is the same issue with AC3 mentioned in another thread.