I have notice that the ui-tabulator node is "inactive" when there no clients connected to the dashboard. Any change or update sent to the node on server side are "ignored" as long as no clients are connected to the dashboard.
That is indeed a problem, since Tabulator is a client-based object, and when there is no running client, the incoming messages are discarded at the server-side. Regular dashboard-2 nodes are maintaining the node's state in the server, so when the client comes up Node-red "replays" the messages to the widgets.
This can work with simple nodes but won't work here since I cannot replicate all of Tabulator's processing functionality on the server side.
I will try to think of something - at minimum to identify the situation and return a response that the table is not up.