Sound keyframes "move" after export making the sound out of sync

Been using PP professionally for years and have come across a new problem.

I'm making a video with music and voiceover.

Whenever I export  from the timeline the voiceover sound works like expected but strangely the keyframes fading the music up and down "move" inexplicably.

I'm exporting in H264, 25 fps, AAC 48k.

Have exported hours and hours of material from the same camera (sony fx3, fx9) with the same timeline setup etc etc so this must be a new type of bug.

In the screenshot the green, pink and blue label are the original files on the timeline where as the purple is the exported wav-file placed on the timeline, you can see the fade down in the beginning is earlier on the purple label (exported version).

Very weird, appreciative if someone has come across the same issue.

Joakim