Zen mode issues

[greenmoon]

We're encountering a couple of issues with zen mode on our platform that I could reproduce with community.nodebb.org as well:

• Since latest Chrome update (Version 71.0.3578.98 (Official Build) (64-bit) and above)
  Zen mode button doesn't work anymore.
  It's working with Edge, Safari and Firefox though.
  Can you fix it or does Chromium/Chrome need to do it?

When zen mode is activated then:

• clicking emoji button doesn't produce anything
• it's not possible to submit a topic or a post in zen mode