Intriguing. This is certainly not an issue we have seen in v10/11, and I don’t recall solving it in the meantime. When you say settings allow them to, you mean they have permissions in Admin > User Admin > Manage Permissions? When you say it does not allow them to do so, can you explain what you are seeing on screen when it does not work?
Adam, thanks for emailing the screenshots. Turns out it was a permission issue in two of the Library files. This is fixed for v11 in this commit:
Get me your FTP details via WhatsApp, and I will fix your version of the files.