This post seems to duplicate the support ticket 1163073 you opened on the same issue.
I will post the answer that helped solving the issue also here so that the rest of the community could benefit from it:
The problem is probably related to the encoding of the CSV file used to provide the data.
We use the StreamReader Constructor (Stream) when reading the CSV data files. Note that this constructor initializes the encoding to UTF8Encoding.
If the encoding of the CSV file is different, this might result in some symbols not been properly recognized.
My suggestion is to check the CSV file encoding and convert it to UTF8.
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