I have something strange going on across all my open workbooks that I have never seen before in 20 years of using excel.
When I use the shortcut for the AutoSum function (press 'Alt" and "+/=" at the same time), my Excel program is automatically replacing the "um()" in the word "=sum()" with the name of one of my worksheets and the cell reference J21. In other words, "=sum()" turns into "=sSHEETNAME!J21". I have tried fixing it using the File > Options > Proofing > Autocorrect tools to no avail. I have deleted my Add-ins and re-started my computer, etc. Nothing has worked. Since I am using MS Excel 2016, there does not appear to be a way to customize the keyboard shortcuts (like in the old Excel 2010) nor can I find any macros that have been created in any of my workbooks that would do this. To make it even more bizarre, if I just type out the word "=sum()" for a formula with out using the shortcut key, that works fine. Anyone have any ideas?