Only a guess.
Do any of the VM's have active snapshots?
If the snapshots were created at a time at which the VM was sill attached to one of these port groups, you may need to delete these snapshots in order to get rid of the entries.
Good Idea. We use Veeam for backup and Replication. I did in fact find VMs with some stuck temp snapshots.
Removing those snapshots caused the switches to disappear.
Thanks for the response.
it was correct , Thanks for saving my day