As a logged in user, go to http://en.m.wikipedia.beta.wmflabs.org/wiki/Special:EditWatchlist (note: behavior is the same whether navigating directaly or as a redirect from Special:Watchlist)
Default List view shows nothing. Click Modified. Many pages appear.
Click LIst view from Modified view. Still no watched pages appear, but they should.
This is the failure at https://integration.wikimedia.org/ci/view/BrowserTests/view/-All/job/browsertests-MobileFrontend-en.m.wikipedia.beta.wmflabs.org-linux-chrome-sauce/436/testReport/(root)/Manage%20Watchlist/Switching_to_List_view/