I am able to work with invoking hookmark context window Shift + Command + space ( ctr +H would also work) t and then copying markdown link by shift+command+M in H6 or command+M in H5.
When I am trying to directly invoke copy markdown link with 'Shift+^+CMD+M` sometimes I am getting link to the item, but sometimes only link to the app
[Zotero Beta.app](hook://application/org.zotero.zotero-beta)
@adry26 chceck with invoking Hookmark window and then copying the link.