Revolution Slider

I have the following problem with Revolution Slider:

There’s the monitorin I see while I edit and the result in the webpage, after updating the slide: is not the same.

1st: there’s another slide under the one I’ve created (and it has nothing: just grey, same size)

2nd: this changes all the location of the text I’ve put on it.

Please, send me some commentaries with some help.

Thank you in advance!