Finding shutdown event in Android bug reports

My Phone which runs on Android 11 has been crashing frequently. This happens randomly - while attending a call or playing a video. I have tried to report it to my manufacturer multiple times to no avail. So, I decided to take and analyse the Android bug report in order to understand what is causing the issue. The bug report generates a zip file - which consists of a txt file containing logs. Is there any generic message which is logged by Android before initiating a shutdown? Or is there any other way - any bug report analysis tool in which I can isolate the events around the crash?