ACM document format vertical space

It is my first time writing a document using the ACM class (sig-alternate). However, I am encountering a big vertical space on the first column of my first page, that shifted 5-6 lines of my Introduction to the second colum (see picture below). I have tried to use the command \raggedbottom but it doesn't change anything. I suppose this is due to the ACM \acmcopyright command, which, if setted correctly, add a small copyright text which almost fill the gap you can see on the figure. Finally, I don't understand how to get rid of the ISBN and DOI for now. On the proceedings I have read which used the same class, no DOI or ISBN appeared. Thanks a lot for your help.

• Solved it using the command \def\@copyrightspace{\relax} – Ecterion Aug 18 '18 at 9:00

To solve it, use the command \def\@copyrightspace{\relax} which is not defined in the ACM sig-alternate guide but in the tex sample.