Image shadowbox in edge theme is broken

Issue Summary

  • When you click the expand button on an image in the edge theme, nothing happens
  • in the JS console “TypeError: undefined is not an object (evaluating ‘t.firstChild’)” is displayed

Steps to Reproduce

  1. Go to the edge theme demo, Edge
  2. Click on the expand button at the bottom right of any image
  3. Notice nothing happens.

Setup information

Ghost Version
5.13.2

Node.js Version
v16.17.0

How did you install Ghost?
Via Ghost CLI. But this issue is also reproducable on the theme demo site.

Provide details of your host & operating system
Ubuntu 20.04 LTS

Browser & OS version
MacOS 12.5.1 / Safari 15.6.1

Relevant log / error output

	getChildByClass (main.min.js:1:20157)
	init (main.min.js:1:27960)
	e (main.min.js:1:4273)
	(anonymous function) (main.min.js:1:4518)
	dispatch (jquery-3.5.1.min.js:2:43096)```

Yes, I notice it too. You are correct, there is a problem.