when creating new Hotspots all required fields are checked during form submit. Except "Description" field.
If I leave Description empty, after form submit I'm redirected to HomePage without any warning and Hotspot is not created.
I'm not quite sure, but seems to me that this issue appeared after Joomla upgrade from 3.4.5 -> 3.4.6.
If you wish, I can give you demo account to my site to test it...