After the Argo CD with Secrets of my Vault works since yesterday, I started today with the migration or the rebuilding of applications that I had previously deployed via Rancher Fleet.
After smaller services such as Diagrams.net and a Discord bot was then also my Matrix server, means the Matrix server of me is now finally back online.
Additionally I fixed my backup cronjobs from Longhorn, because they were not applied to any group, so no automatic backups were made.