Toggle button that will hide/unhide columns within a range
You use ActiveWorkbook.Sheets("Notes") 5 times, throw that into a variable or use CodeName property - View Properties window (F4) and the (Name) field can be used as the worksheet name. This way you can avoid Sheets("mySheet") and instead just use mySheet.

You don't need to Call subs, it's obsolete. Instead just use Sub argument, argument

As far as troubleshooting the second, that's not really on topic here because it's not working. But what is -

Call ActiveWorkbook.Sheets("Notes").All_Sheets_UnProtect("Notes")


You were using

Application.ActiveSheet.Columns(xAddress).Hidden


and then changed to

Range("NAMED_RANGE").Columns.Hidden 


It works for me. If your sheet is changing, it might fail because you don't specify the sheet.