According to the Magento 2.1 frontend developer documentation (http://devdocs.magento.com/guides/v2.1/frontend-dev-guide/layouts/layout-types.html#layout-types-page) it should be possible to create a 2columns-left.xml specific layout file at
<Magento_Theme_module_dir>/view/frontend/page_layout/2columns-left.xml but I do not wish to do this for a specific module. I need to modify the layout of all 2columns-left pages (from any module) for my entire theme.
I've tried creating the file at
<Magento_Theme>/Magento_Theme/view/frontend/page_layout/2columns-left.xml but it is NOT working, it seems like this file is being completely ignored.
I have successfully modified page layouts using other handle specific layout files but can not get it to work with any of the CMS page selectable handles (2columns-left, 2columns-right, etc).
Has anyone else experienced this problem and found a solution?