Why can't I select any cell, even unlocked cells, after my program runs unless I unprotect it?

[USAMax]

I am creating a form that the first person only needs a little access to but they need to see some fields but no rights to them.

The next person needs to see what they entered but should not be allowed to change it.

The last person needs full access.

To protect the cells I am only using three commands:
.EntireColumn.Hidden
.locked
.FormatConditions

I have not gotten to the point where I protect the worksheet but after running the program I cannot select any of the cells including the cells that are not locked but I can double click on them.

At the end of the code I added:

ActiveSheet.Unprotect

The really strange thing is that the unprotect worked but I had a different worksheet selected. I unprotected, "Sheet 1" and not, "Master Item Information".

 

[USAMax]

I don't know why but it works after I enable or disable protection after I run my code.

The problem is fixed but I would still like to know why this happened.