Edge labels are not displayed

here is a sample graph

digraph G {
node [shape=box, fontname=arial];

user [label="node"];
{ rank=same; client_app [label="node"]; wallet [label="node", shape=cylinder]; auth_db [label="node", shape=cylinder] }
{ rank = same; fabric_ca [label="node"]; ca_db [label="node", shape=cylinder]; }

user -> client_app [label="1"];

client_app -> auth_db [label="2"]; // this label is not displayed
auth_db -> client_app;

client_app -> wallet [label="3"]; // this label is not displayed
wallet -> client_app;

client_app -> fabric_ca [label="4"];
fabric_ca -> ca_db ;
ca_db -> fabric_ca ;
fabric_ca -> client_app ;    


it can be tried at http://viz-js.com/

Note that it does not display two edge labels . why is that and how can it be fixed?

I get this warning:
Warning: Orthogonal edges do not currently handle edge labels. Try using xlabels

dot version: dot - graphviz version 2.45.20200731.1442 (20200731.1442)