Adobe Sign (Google Extension) Changes a One-Page PDF into Two Pages

My employer's one-page Excel file requires my signature to appear on that single page. I convert it to a PDF, upload it to Google Drive, double-click the PDF then use the Open With... option to access the Adobe Sign extension. At this point Adobe Sign magnifies the PDF so it is spread out over two pages, with no way to scale it back. Why does this happen and how can I fix it?

I don't believe that it's the extension causing the issue because I've had this happen from within the EchoSign site, too. I'm open-minded though so tell me if I'm wrong.