This has happened before.. Not sure if its my workflow or a bug.. I can delete the hotspot and reset it but then it will come back again where I do not get to see the 3D view, and where it seems to goto a different part of the UI.. I made up a video since its too hard to explain..
Also, while I am at it.. I made up a Tour to test this where the full screen works and exits fine, url below.. But this link above, the exit full screen does not work.. It dependent on the plugin used or the media added to the Tour as to whether the full screen exit will work.. Its kind of frustrating since I knew there was an issue but to narrow it down to what it could be is a pain.. This demo Pano above has a Kolor Website Box.. This must be the block to allow exit of full screen. This is also apparent when I add my own 3rd party media.. Therefore, its NOT my media thats causing it, but rather something else..
You can see here at this link, my Tour without a Website Box.. It works fine..
If anyone get this effect happen in your 3D view, it is related to the ratio of your pano caused by the fact that PTP export cube faces then rebuilds a pano that does not have a ratio of 2:1..