Supervisor depends on a particular version of Docker CGroup to be in use since it depends on its features to work properly.
Currently Supervisor requires CGroup v1 in a supervised installation.
However, the feature set changes and improves over time and therefore, the minimal required version may change in the future. When that happens, it will be communicated before we publish a version that will require you to upgrade CGroups.
In a supervised installation if you have switched to CGroup v2 you will need to revert what you did. Or you can re-run the supervised installer to fix it. Please be sure to reboot the system after the installation is done.
You should never see this issue on Home Assistant OS as all versions of the OS ship with a supported CGroup version.