Adding a "featured image" in admin

Hi guys. Im trying to add a “featured image” on some pages on a multilanguage site.
Using the file upload or the pagemediaselect in the admin updates only one language .md file.
I thought about renaming the file on upload but couldnt find that option either (i dont want to have the client having to rename, i wanna make this easy)
Is there a way to update both languages, or to just have the admin read whichever image is under a /page/header folder or something?

Thanks for your attention!