Your site is designed with a specific padding around each page so that the site appears to have white space around all of the content.
To keep the site design consistent this padding needs to be set the same on every page.
After you create a new page and enter the Elementor editor, click on the page settings icon in the top left hand corner, then click on the style icon below it and set the padding numbers as I have them highlighted in the image. Then click ‘Publish’ in the upper right hand corner to save your page settings.