For future reference, I’d like to thank you @JeTFiN for going through us over the process of gathering logs and testing out the issue.
The DZ6HD-1BZ does support lifeline reporting of its status when switched on/off manually at the switch, however these switches weren’t. Unpairing the devices and re-learning them into the network using Network Wide Inclusion does the trick of re-exposing the Group associations settings to the controller to keep up with the updates.