I've noticed a bug with creating the thumbnail of a project.
When I press "Publish" in some projects, invisible clones of an object turn visible.
In another case, clones of Octo that have "set text" turn into regular Octo when a thumbnail is created.
In the Octopus project: (which is a draft)
And the thumbnail for that:
I'm not sure if this bug is possible to recreate.