Kie server should be synchronized with Kie server router immediately after Kie server router starts up and not only after you add some container to it.
There could be applied same connection logic as is used for connecting of Kie server to controller.

This applies to case when Kie servers and Kie server router are connected to each other and to controller. Also affects just a situation when Kie servers are started first, Kie server router is started lately.

If Controller has containers defined for server templates, Kie servers install these containers immediately after their start. If Kie server router starts lately, it doesn’t have any informations about those installed containers.
Idea is that if Kie server router is not available on Kie server startup then Kie server will periodically check router’s availability and when it becomes available then it sends its container info there.