Audio with Markers

I have presentation A with audio and markers to sync with animation.

presentation A's .PPTA file is corrupted.

Now, i am importing all the existing slides into new presentation(presentation B) with the animation.

I am able to export the audio files from presentation A, to import them in presentation B without problem.

But the marker sync is lost..or positioned properly.

How to bring the sync without doing it manually again.

Thanks in advance.