Custom link sub menu error – links to post not page in menu

My main menu has a page with several sub menus (custom links) that link to named anchors on the page. This was working and nothing was intentionally changed re: the menu. But now when selecting the sub menus, they are linking to a post and not the page entered in the custom links. The link still shows the anchor, but it shows the incorrect link to a post rather than the page. Thanks for any clue.