If you try republishing with "show sheets as tabs" unselected (I know you tried this before) and remove all ability to download and web edit, does the issue persist?
Diego, thank you for your response. I did try that without success but what did work was explicitly denying access at the View level per group that I didn't want to have access. I thought that if I did not give access that others would not be able to see the views that I did not want them to but that wasn't enough. I needed to deny access. In terms of the URL, I sent everyone the workbook URL and everyone could only see their own Views.