On mobile devices, a blank space (a gap) appears to the right of the website

This can be caused by:

• A third-party code. For example, if the embedded iFrame is not responsive.
• The sum of the left offset and the width of the block exceeds 12.
• A long text string, a link, for example.

It is quite easy to identify the reason. Scroll to the right until you reach the edge of the screen. Then scroll down until you see what has caused the problem.