A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
First - Reinstalling Mac applications is almost always a complete waste of time - apps just don't corrupt very often. Unlike Windows, which often resets the Registry when installing an application, Mac installs rarely touch Preferences, which are far more likely to corrupt.
It looks to me like Calculation is set to Manual. Change to Automatic in XL Preferences/Calculation.
Calculation mode is a workbook preference, so XL takes on the value of the first workbook that is opened during a session.