this looks weird because you should definitely see the other nodes as welland the pvesh get
you should fix your cluster before further trying to migrateIt looks like the routing on the private bond0 interface (meshed networking between the nodes) is not working properly for the clustering.
what does pvecm status say?
also your corosync conf looks wrong for multiple rings, see https://pve.proxmox.com/wiki/Separate_Cluster_Network#Redundant_Ring_Protocol