17.4.2 Build 9 bugs, stops responding

(Mac Mini M1 2020, OS Big Sur 11.4, Memory 16GB.)

1. While moving a multicam clip on the timeline from one part to another, Davinci becomes non-responsive and we have to force quit.

2. While saving or creating a DRP file, Davinci also sometimes becomes non-responsive.

3. General slower functioning than previous update.

Which sources, which timeline resolution? A M1 Mac mini is pretty limited by its GPU.

Footage is shot in "AVCHD MPEG-2 Transport Stream" in a 1080 timeline.
I have heard Apple ProRes is best to shoot in, but we don't have that option currently.
I've created Proxy files and Optimized media as well. Viewing in 1/4 resolution with color grading shut off.
The problem is it WON'T SAVE after I've moved large portions of the timeline to different places.
Thanks for your help Uli.

Which format are those proxies?

Proxy media is H.264
Optimized media is ProRes 422 HQ

Try ProRes LT instead of H.264 for the proxies.