Update: Macbook pro 16 restarts every 12 minutes. I could transfer vital files from mac hd to an external drive after 15 times restarts. in meanwhile I download Catalina as well. first try to make a bootable flash was failed. coz it takes more than 12 mintues. I tried on faster sd card and it works. I've done clean install with Catalina. It works well. #BigSur beautifully sucks. never ever upgrade.

Same problem here on 11.0.1 (20B29) and it's not a beta version. This gonna be killing me. any solution?