Shortcut to NAS fails to open spreadsheet

I have a QNAP TS-210 network attached storage with an XLXS file I would like open from a Desktop Shortcut. I am using Linux Zorin OS 12 64-bit. I can open and save the file without a problem by navigating to the file location. I can create a desktop shortcut to the containing folder which functions normally. But when I create a desktop shortcut directly to the XLSX file I get “General input/output error while accessing”. I get the same error if I use the folder shortcut from the File - Open menu. This problem does not occur with other files, such as PDFs. I have tried LO versions 5.1 and 5.3.

Thanks for your assistance.