Error: All provided root_pr_nodes must be present in the principal graph. error in monocle3

Question

[kayah]

root_pr_nodes <- get_earliest_principal_node(cds_embeddings)

print(root_pr_nodes)

graph_nodes <- igraph::V(principal_graph(cds_embeddings)[["UMAP"]])$name

print(graph_nodes)

cds_embeddings <- order_cells(cds_embeddings, root_pr_nodes=root_pr_nodes) Error: All provided root_pr_nodes must be present in the principal graph

I'm curious why this error happens all the time... I can't understand that the roop_pr_nodes present over the principal graph.. Is it possible and how to handle this problem