XDJ RX Beat suddenly drops offbeat.

Hello , i've got my XDJ-RX a few Days ago. 

Yesterday i noticed some odd problems with some of my Tracks. I dunno if it is more a rekordbox Problem or a XDJ RX Problem.  Let me give you a Example:

While mixing i noticed that the beat from some of my tracks suddenly drop totally offbeat. That means the beat of the Track goes out of sync totally. Its like a jumping CD for a short time. 

I tried to reproduce the Problem and detect it in the Track itself .  It seems that there is a certain spot in the track where it goes offbeat. Alswo while searching via Vinyl Mode through the Track ( Spinning the Jogwheel slowly around that certain Spot. ) i can hear that the track is damaged.  The Waveform on this spot also looks a bit curious. 

Even with the Sync Funktion the beat goes totally out of sync.

So i thought my track is damaged. 

I deleted it from the Rekordbox library. And import it again. Analyzed ----- Same Problem

Tried to play the Track via Link funtion on the XDJ ----- Same Problem

Tried to export it on a USB stick and play ----- Same Problem. 

When i Play the Track without the XDJ RX, via Windows Media Player and also on Rekordbox itself ( The In Programm Player). there is no Problem with the Track.

Then i deleted all  Files from my USB stick and dragged only the Track on the device. Without any Rekordbox files or analysis.

Put the Stick in the XDJ RX and play the Track -------- NO PROBLEM.  The track runs smooth.  ( Off course no Waveform because no Rekordbox data)

It seems the rekordbox analysis does something to my Tracks and i only get the Problem when i run the Tracks via the XDJ. 

I noticed this Ploblems on other Tracks also. 

All Tracks are purchased on Beatport or Amazon Music. 

Rekordbox and the XDJ RX runs on newest Firmware.

Next step i will analyzing my Tracks with your suggested programs to look if theres Problems with the Tracks. 

Maybe somebody has the same Problem. 

Any suggestions ? Its totally Annoying -_-