Missing audio files- but not all of them

I have seen and read through the threads about missing audios after publishing. Mine is slightly different in that only some of the audio has dissappeared.

I did save the file under a new name but in the same folder, the new PPTA  has been created with the same name (no old.ppta exists.) I was working in audio editor to fine tne a number of slides. Then published.

The published version only had some of the slides with audio.

I went back into audio editor and the audio has dissappeared some of the slides.

I am guessing that the ones that still exist were ones that I editted today after saving under the new name.

I never leave audio editor without saving, and they were all there before I published.

What is going on?