Virtual Machine not access and not monitoring metrics

Summary

virtual machine, connection issues

Content

I have the issue that I set up a virutal machine on ubuntu, which runs easyengine (easyengine.io) and the VM is from time to time not accessible via SSH and also the websites hosted on it are down.

When I try to access the machine I get the error "kex_exchange_identification: Connection closed by remote host". When I check in the Oracle cloud dashboard the VM is running, but there is not metric data available for this timeframe. Afterwards the VM is accessible again without any change. Firewalls I checked already, everything is configured correctly.