I saw someone else had this question for Excel 2010, but it was never properly answered and I will be more specific as to what is happening.

In Excel 2013, only when I am working on a PROTECTED sheet, if I have cell A2 selected and try to use the left arrow key, instead of stopping at A1, it cycles the selection all the way over to AU2!

I've also tried the suggestion to simply use the "home" key to go to the beginning of the row, however, it does not take me to A2, it takes me to E1. 

Can anyone help with this??