Thanks for the report.
The hierarchy view currently only syncs one way: clicking a node in the tree selects the control on the canvas, but selections made on the canvas (including the automatic selection of a control you've just added) never flow back to the tree. So when you switch to the hierarchy view the tree shows nothing selected, and after you deselect on the canvas the tree keeps the old node highlighted. A side effect of that stale highlight: clicking the same node again does nothing until you click a different node first.
By contrast, the desktop designer's hierarchy view keeps the selection in sync in both directions, and the web designer will do the same once this is fixed. It's tracked here: https://feedback.objo.dev/bug/1559