No text area in Expression Editor

There is no text area in te Expression Editor. If I hover over the line number I can see the text that has been added, in this case the Parameter Titel, but there is no place to actually edit the text or see the full extent of what has been written. Does anyone else have this issue? Is it a new bug that was introduced? Is there a workaround?

I've tried Edge and Chrome to see if that was the issue, but it's the same in both browsers. Using the online versionand the new Layout-based Printing Engine