Issue with the cleanConnectorMap in ConnectorTracker

Dear Vaadin gurus,

In an application I’m working on, I can see in the log file many messages related to the “issue” method in vaadin com.vaadin.ui.ConnectorTracker class.

cleanConnectorMap unregistered connector ch.unifr.se.common.ui.component.Labelable(2024) (parent: com.vaadin.ui.CssLayout(2022)). This should have been done when the connector was detached.

it is logged by the following piece of code:

...               
// This code should never be called as cleanup should take place
// in detach()

getLogger().log(Level.WARNING, "cleanConnectorMap unregistered connector {0}. This should have been done when the connector was detached.", getConnectorAndParentInfo(connector));

is there here a know reason why this would happen ? or some path I could follow to hunt down some eventual incorrect java code that would lead to such result ?