Garbled text in Whoops error screen - utf8 encoding

When I view page info for this screen it says the encoding is UTF-8 but it's not showing up correctly in the browser window. This issue affects all UTF-8 characters, not just the "shrug" emoticon in a comment...

https://www.screencast.com/t/DrZutYi1zb

Here's a test case with everything you need: https://www.dropbox.com/t/HYA2n7pwICHUwvMB

Unzip then "box start".

I am using firefox on windows 10, if that makes any difference. And I'm sorry about the new case. You closed it and I don't see a way to reopen and add information to it.