All of a sudden, the mobile view/design functionality for pages (not properties) = 0. No plugin conflict seems to be the reason. On desktop it works fine.
Problem is now solved. It was an issue related to caching. For some reason the removal of cache for mobile devices was not working. I’m not still not sure why, but I write in case anyone else has similar problems. I had to install another cache plugin and remove cache, then it worked.