Lightroom Classic crashes when working with collections

Hello all, on my iMac i am using MacOS Catalina 10.15 and Lightroom Classic latest version.As i am working with collections, suddenly lightroom freezes then a white pop-up window appears making Lightroom totally irresponsive. I have disabled GPU acceleration as many other cases with the same issue existed ,disabled all add-ins/plugins and did a back and forth with all Lightroom classic editions available ( keeping the same catalogue format), yet the problem remains. I am forced to go to the latest backup of my catalogue almost everyday. I also have a macbook pro 2018 and facing the same issue as well ( same OS , same Lightroom version ) 
I have submitted the crash report to Adobe automatically with no luck. Any ideas??

thank you in advance!