I have observed that the password manager's export csv format is not read correctly by Excel. If I create a note with multiple lines of text, I expect the body of text to be inserted into one Excel cell. Instead Excel breaks the note into multiple lines. The problem seems to be that Excel fails to interpret your Unicode UTF-16 LE encoding correctly.
Not expecting Microsoft to change as I think this is a long standing issue, it would be useful if you could export the csv file in 'Big Endian' encoding, --or-- perhaps a better solution would be to keep your 'Little Endian' encoding but provide an option for 'tab' as a delimiter. For some reason Excel is happy with 'LE' + 'tab'.