some times NVDA screen reading blank when node is expanded and clicked. revisit on the node again. At some point NVDA reading as blank. In this example https://circlongroup.github.io/angular-tree-component/ go to Examples-> columns 
some times NVDA screen reading blank when node is expanded and clicked. revisit on the node again. At some point NVDA reading as blank.
In this example https://circlongroup.github.io/angular-tree-component/ go to Examples-> columns