This in my development machine. Currently developing with React + Meteor 1.4.
I use Google Chrome dev tools to see responsiveness on different smart phones and tablets when suddenly today I find responsiveness gone. I made no major changes to any CSS files, reset my project, restarted my app and still no responsiveness.
I had a similar problem like this in my previous Meteor apps using Blaze. I solved it by adding the viewpoint meta tag, but this can’t be done with my React + Meteor configuration.
When I shrink the browser manually, it is responsive completely and have no problems. When I use Google Dev tools to see different views from tablets and phones, it’s not responsive.
One thing I like about computers is that they are consistent. If nothing changes, nothing will change. Therefore I suggest you check also the minor changes in the CSS and HTML before investigating the ambient domains.