You asked: Would this make a difference if there is a hidden column or two when I sort?
The answer is yes, if at least one of the hidden columns has no entries. The 'expanded' section only extends to any row/column that has no entries in cells adjacent to the area you are expanding. Graphics below show results of starting a sort just choosing the LName column then responding Yes to "expand" option with a Custom Sort. I used Custom Sort so you can see what it expands to. If you just use A-Z/Z-A sorting it happens so quickly you can't really see it unless you watch very, very closely.
As you can see, because of the empty column D, the street/city/state/zip/phone data doesn't get included for the sort.
BUT!! By simply adding a 'dummy' label in row 1 to give the section continuation across otherwise empty rows, you get what you expect: