Meta tags appear on both nodes (node/6) and taxonomy term listing pages (taxonomy/term/6) without page manager enabled. But when page manager overrides the output of those pages, meta tags to not display.
Turning on panels, page manager, and creating a page manager override of node/%node, adding a variant, placing a content pane for Node: Content (Full node view mode) into the panel, and viewing the page, indeed, does not show the metatags anymore for node.
Creating a similar page manager override of /taxonomy/term/%taxonomy_term, adding a variant, placing a content pane for the term (or view) into the panel, and viewing the page, also does not show the metatags anymore for term.
This is not a duplication of #1151938: Panels integration - meta discussion -- this patch allows defining metatag for node, and get them also if Page manager is overring the node view.