I am having a similar problem.
When I click on the “Print” icon, it initially prints everything on the page, including the site header.
However if I cancel the first print attempt and then try it again straight away (without refreshing the browser or clearing the cache), it prints the target content correctly.
I am using the plugin on a food blog I am building using Elementor, and calling the print shortcode via an Advanced Custom Field link.
I am confident that I have the shortcode and also the CSS Class on the section I want to print entered correctly, and the fact that it works on the second print attempt seems to bear this out.
However, I am concerned that a potential user may abandon the recipe and the blog if the first print attempt always results in extra unwanted content.
I would appreciate any comments or assistance.