Unable to add anchor to header

I have got a question regarding adding an anchor to the header. It has indirectly to do with Wix Code. I made a floating header/menu, which looks and works fine on the home page. I’m unable to create the same effect on other pages even though I added the code to the Site Code. I’m pretty sure it has to do with the anchor that I placed in the header. I’m simply unable to drop the anchor in the header. Whatever I try it keeps saying “attach to page”.

Is this just a glitch on my site and should I ask Wix Support or is there something on my site that would prevent the anchor to be dropped there?

I currently have two strips (a small and a big one) in the header and two menus that are attached to the two strips.

Right, Anchors can’t be attached to the site header.
I think that what you’re trying to achieve with your header is possible - there are several discussions about this topic in the forum, for example - https://www.wix.com/code/home/forum/questions-answers/how-to-create-a-sticky-header-menu