This literally started happening a few days ago when an external event happened (the kernel was updated) and was isolated yesterday from info in this (among other) threads. It’s not something we intend to be unsupported; stuff happens and it will be fixed.
As far as the support matrix goes, support (for people that are customers) is only for installing Rancher on to a cluster with Helm… The docker container and its embedded cluster is basically for development and demos/kicking the tires. Customers aren’t running on one container with ephemeral storage.