I suppose the plugin’s content can only be displayed in the content area of the post/page, GP’s element is a custom post type which the plugin might not support.
I would recommend reaching out to the plugin support ask how to add support to custom post type.
you have a Header Element ( in Appearance > Elements ) which is set to merge the Site header with the page content.
I am not sure if you require this elsewhere on the site.
If you do not – then delete it ( or Quick Edit and set Status to Draft to disable it ).
If you do require it elsewhere – edit it and change the Display Rules.
This hasn’t got a merge / transparent header option?
Correct, Block Elements do not have the option.
The merging is being performed by the Header Element titled: Transparent Header. Thats ALL it is doing, just merging the site header with the top of your page. You need to edit this, and Exclude those pages from its Display Rules.