Ref T13202. See https://discourse.phabricator-community.org/t/phriction-page-controls-lost-after-creating-very-wide-table/1961.
If you put a very wide table in the markup for a new-layout Phriction page, it can push the actions element off screen to the right.
Tables already get a scrollbar if encouraged strongly enough; add a max-width to encourage them.