Hi
Your next career move?
Is a CTA Style 3 module and the height of the module is depends on the content inside it directly .
On the other hand on your site its Hero style module. the height of the image is used by background size that is 100% of the image .
If you want to add max height , you can use a module suffix in the module and define the suffix class in custom.css file .
For example : csheight is suffix
you added in custom.css
.csheight{max-height:600px;}
Or apply it directly using module id
#section-175 .full-screen {max-height:600px;}