21in late 2012 iMac with Catalina - keeps randomly rebooting

I have a late 2012 21in iMac that is currently running on Catalina's latest version. After the last update to 10.15.7 it keeps randomly rebooting. Without any specific reason and without any warning.

I have already done a clean instal of Catalina after erasing my hard drive.

Pls help resolve this issue. Thanks in advance.