Could you provide some more details about the problem? A screenshot might be helpful. If you click the "Reply" button, you'll see an "Attachments and other settings" link that will allow you to attach an image to your reply.
I also couldn't reproduce the issue in the Chrome browser. The problem seems isolated to the Arduino Create Chrome App version of the Arduino Web Editor.
Your thread has been moved to a section of the Arduino Forum that the people involved in the development of the Chrome App monitor so I'm sure they'll look into this soon.
Note that the browser addons are in the Windows 10 Chrome, and they seem to be fine. This is only on the Pixelbook. Everything else seems to be fine, and i do a fair bit of web based editing. This is the only application that is having this issue.