Audio cannot copy/paste to new file

When I added an audio file to 'File A' and used 'audio event' in an Artboard.

Then I copied this artboard and went to another 'File B' to paste it. At this point, the applied audio files cannot be pasted together.

The applied images and fonts can be pasted into the new file normally, except for the audio file which cannot be pasted. I hope this issue can be fixed.