How to find the root cause for daily crashes?

Within the last weeks I have again and again crashes with my hass.io on my raspberry pi.

Sometimes it does not happen for a few days but currently it is happening more than once a day that I cannot reach the homeassistant via the android-app or the browser and I have to restart it.

I am always running on current versions.

When I am checking the log for problems I only see log entries starting with the latest reboot, so that I cannot find anything within the log that might show, what has happend before the crash.

Any idea, what I can do to find the problem?

Logs are cleared on restart. Login using SSH before restarting to view the logs:

Several reports during the last months, have a look at a big collection at https://github.com/home-assistant/operating-system/issues/1119