This may be due to the type of file you are editing.
If you go to Tools / Options and Rules and determine which rule applies to the files you are comparing, then look at what is selected on the importance tab.
For example, if you are editing / reviewing the rules for Visual Basic files, you should notice that the case with the symbol is marked as irrelevant, but it is not marked for C / C ++ files.
, , BC, , .