I do understand your situation here and that you are not a technical person, but unfortunately the solutions to the problem that you are experiencing are indeed technical and we can not go over every page that you added with none standard way and see why the problem is happening in the Chrome or any other browser/
I did my best and did a complete analysis of the about page and found out that the section with the HTML ID of
x-section-9 uses none standard code for the Parallax effect and that is causing the issue. So you need to go to X > Theme Options > CSS and add the code below:
The code above forces the section to go over the top and show the background image.
I am not sure if that is the case for the other pages but indeed it will be impossible for us to go over all your pages and find what you did right or wrong.
I strongly urge you that you read the articles in the Cornerstone / Content Builder section of our Knowledgebase by clicking here. Also, you need to educate yourself on using the elements by checking the Elements section articles in the same link.
We can not guarantee the correct work of the theme unless you use the recommended way of page creation and Page Builder usage.
Hope I have honestly explained the situation. Thank you for your understanding.