Copy worksheet from one WB to another, overwrite existing worksheet with same CodeName

Ok, apparently copying the worksheet now removes ALL cell comments. I don't understand this. The worksheet in MasterBook has all comments, but when the ws is copied over to UserBook, the comments are all gone. They're not hidden, they just don't exist. WHy would copying the worksheet not copy the comments on that worksheet?

I am only having this problem in my large project. The small sample files DO work properly, including copying the comments over. But when the exact method is applied to the larger project, the comments do not get copied over. Furthermore, I get the same problem when I manually copy one cell that has a comment in it from the master workbook and paste it into a brand new workbook. The cell value and format are copied, but the comment is not copied. It worked before, but now it doesn't. WTF?