Actually browser normalized string and it works for me also. Here is original byte sequence:

    >>> b'n\xcc\x83'.decode()
    'ñ'
    >>> b'n\xcc\x83'.decode()[0]
    'n'
    >>> b'n\xcc\x83'.decode()[1]
    '̃'

But I agree, it's rare case when you need to deal with non-normalized data.