Hello,
Your issue is now resolved.
Actually, you had a HTML Block widget added under the Dashboard > Appearance > Widgets > Footer Column 1 but under the Dashboard > Theme Settings > Footer > you had selected the Footer Columns layout structure as 5 Columns which is why that gap was appearing. If you want to use the HTML Block for the Footer having all the content in the single block then you must also select the Footer layout structure as 1 Column which we have selected now: https://snipboard.io/u0mWGH.jpg
This is the resultant preview now on your Site: https://snipboard.io/m98YsC.jpg
Please check back your Site after completely clearing the browser and server cache.
Best Regards.