CDJ 2000 Nexus skipping while hitting Loop in

Hey guys - having some trouble using my CDJ 2000 Nexus. They randomly skip a half beat while hitting a loop at touch-section. 

I have recorded this, watch videos:

Normal behave:
https://youtu.be/obcd13MwxgQ

- Even if i dont hit in time, no probs.

Problem behave:
https://youtu.be/ZdWsOmQs0_E

- everything broken... (sorry for short clip)

This Problem:
- happens to other People with other Sticks too,
- happens randomly,
- happens to new analysed Tracks too,
- happens not with my Nexus2...

Any Ideas about that? 

CDJ 2000 Nexus, Quantize on, Master Tempo on, Firmware 1.43 

Thanks Guys!