Editing multi-line HCL variables displaying in single-line text boxes in web UI

I can paste a multi-line variable and it works fine, however when i try to edit it, it’s displayed in a single-line text box like this:

I can work around it by copying the value into a text editor, editing it there and then copy and paste back into Terraform Cloud, but that is pretty painful.

Do I need to do anything different, or is this a bug? I’ve tested in Safari, Firefox and Edge.

I reported this to Hashicorp. They have confirmed it’s a bug and they are working on a fix.