Hi,
I just tested your project on our latest version. I was right: is only working in non-clustered mode. So, we have a bug in EMS: EMS is not transporting the sharedObject events between edges and origin. So, when you have n customers, x are connected to edge1 and y to edge2 where n=x+y. Because of the bug, changes made by y clients are only visible to y clients, not to x as well.
A quick temp. fix is to launch the server in non-clustered mode: put instancesCount=0 inside the configuration file. The current /default value is -1 which means automatic instances count. 0 means disabled
Best regards,
Andrei