max-santiago
Hi
The masthead image load behind the text heading and description as background image.
If we force it as full responsive it will not cover the complete background.
+ the Height of masthead section is nearly 360px but you have added an image of 1920px X 1200px that is way big to fit.
this is code you can add in custom css to force background as 100% width but the big image will still not work as the container size is small
.ja-masthead { background-size: 100%!important;}