2-10 SECONDS FREEZE EVERY TRACK IN 6.0!

i'm writing now the third time and we are several DJs. Until now there is no answer from RB support.

The problem: 
If i use realted tracks window to show me the tracks i already played before/after the current track, it freezes. It freezes with tracks, that i played a lot. Tracks with more than 200 play counts need more than 10 seconds (beach ball), 100 played songs freeze 5 seconds. new tracks have no problem (you can see it in the video). 

It is not an issue with my macbook (2017, 2.9Ghz, 16GB), it is not an issue with lightning/lyrics or something on (everything deactivated). It is not an issue with the latency, using 11.6 MS. 
i did NOT have this issue with 5.x versions.

AND: I really need this function and it is the greatest advantage compared to other software. 

As a professional DJ it is very frustrating to have a frozen desktop every song!

I'm writing the second time now. Would be nice to have a helpful support.

the Video is here: https://drive.google.com/file/d/131siEDi-dx1-iNdlWMDomefgqDTTYn-L/view?usp=sharing