Excel needs not to be closed but needs to be saved for Excel Advanced
Q. Do you have to close the Excel file for "Excel Advanced" plugin to read from the file?
A. No you do not need to close the Excel file for READ options of Excel Advanced. However you must save the Excel file after updating it for the Excel Advanced plugin to handle the latest data in the file.
Please note that Excel DOES need to be closed when Excel Advanced is used for WRITING.