Question on artboards and responsive design

Hello! I have a question on artboards and responsive design.

I recently inherited a plasmic website, and I am trying to understand why some of our pages have an empty artboard (see first image) while some pages have them (see second image).

Questions: Is this something that can be fixed (i.e. populate the desktop sized artboard)? How do you do that?

Thank you!

Hey, can you send me your project id?

sent it to you, thank you!