There is an extra gap on the left side of the website

Hi,
There is as a gap on the left side of the web page which was not there before. I have deactivated the subheader, any newly added plugins, etc but to no improvement.
I felt that it appeared after I recently enabled the subheader through theme options but that is only my hunch.
Another observation I have made related to this issue is that when I minimize the view to the smallest browser size then go back to the full view, the gap disappears. But, after a few seconds, it returns.