Trigger not working when published

I published to the web and ran it seven times, each time starting with a different leaf. Each one changed to the Visited state when I selected it.

The one thing I would suggest is that you not use groups for the leaf and the text. You cannot move either one of them without moving the hotspot (which you won't do accidentally), and your learners cannot move either of them. So the group is not serving any practical purpose. Groups are well know not to play nicely with states and triggers, and can potentially cause the sort of problems you are experiencing.  Since it works for me, I can't test to see if groups are the problem, but even if it doesn't resolve this problem, not using unnecessary groups can save you development time and resources, as well as potential conflicts in the future.

The other help I would offer you is to suggest that you drop the tree into a graphics editor such as the free paint.net. With a few clicks, you can fill the leaves and birds with black, saving a bunch of time and effort.