External user unable to edit SharePoint list (modern view) or view details pane

Hello,

I have a SharePoint list set up and shared with external collaborators. They are only able to edit in the Classic View - when they tried in the Modern view they are able to see the list and click to view the details pane but the details pane shows up blank.  Is there any fix so they could use in the modern view?  Its only happening with selected viewers, some are able to edit in Modern view just fine. 

thanks!