How to populate a textarea (medium-editor) with content from a variable

I have a variable ‘list_replace’ which is populated dynamically and typically looks like this

• list_replace: “Repeater lamp, Headlamp, Stop/driving lamp, Screen Pillar”

Now I want to populate a textarea (medium-editor) with the content from the variable, but I can’t get it to work.

If I try to populate a standard text input, then I can get a result.

I know textareas are slightly different but I’m not sure what to do here.