This issue just started happening and is a huge source of frustration. I hava been a loyal Traktor user for over 15 yrs and this is the first time that I am really annoyed by this. 
I know you are going to ask me to start looking at settings and stuff and that is PRECISELY what I loved about Traktor, its stability. I am for the first time in decades I am thinking of switching due to this. 
I am hoping that you can release a newer version which simply fixes this. I read it is a common problem and it is not just unacceptable, it has made me loose confidence and be nervous about it. 
I am in 4.20.34 with a brand new Mac on latest OS 
Fix it