@mastadamus I will bump up the memory limit for vault. https://learn.hashicorp.com/tutorials/vault/reference-architecture says 4-8GB is recommended. Currently, the cloudron package runs at 256MB!
Also, as you guessed, it's only the vault container that is dying and the server is not affected (I guess that's one of the main benefits of running in containers, a single app cannot bring down a system).