I wonder if it’s by design that Gantt plugin is not showing links, for example child or dependencies. or I’m missing some details on how to use it correctly.
Unfortunately the current gantt js libary doesn’t support links between tasks.
In another project I’ve used https://github.com/DHTMLX/gantt maybe it’s time for another more complex kanboard gantt plugin
see also github issues https://github.com/kanboard/plugin-gantt/issues/19
If anyone wants to implement a more complex Gantt plugin, we are ready to donate for acceleration.