hey i have a similar problem i think.
i have just copied a website that i created on the domain http://www.mobilebarber.ch and exported and imported with the wordpress plugin All-In One WP Migration to the domain http://www.cabrioleballett.ch. Everything works fine except of the header. the Header gets now transparent as soon as i scroll down on every site except of the page “Unterricht”. I have no idea why this page is different than the others but the goal is that every site is like that.
Please help
Thank you in advance