wierd m4a audio problem i only have on my mac

Hi,
I recently bought a brand new macbook pro 13 with touchbar and high sierra. Some aac m4a files (no drm) have this wierd problem that there are multiple sections of silence in the song, some of them almost a full second long. Even in the waveform those sections show as a flatline. I dont have this problem with other formats. I dont have the problem if i play the same file on my mac with itunes, virtual dj or a trail of dex3, not even when i play the same file on Rekordbox on my win 10 laptop. I tried exporting a playlist of those files from rekordbox on my mac to a usb stick and playing them on even more computers with vdj and rekordbox, they all played with no problem. Has anybody else encountered this problem on osx? Half of my music library is in aac m4a so it would be quite a hassle to convert them all... I really would prefer taking my macbook instead of my older cheap plastic laptop on gigs....

Best regards,

Kevin.