If you have tested attaching a cluster to Kommander and then tried to detach it only to see that it never self-detatches and you are using Konvoy 2.1.1, Please see the following documentation here:
There is an issue with Kommander that can prevent any cluster from being detached if any one cluster currently attached to it does not have the cert-manager resources updated as linked above. Once you apply this fix to every cluster attached to your Kommander cluster, the issue should be resolved and your clusters should properly detatch.