EDIT: I can't seem to replicate this on my Ubuntu system. Strange.

Ah, interesting, I suppose then there is a difference in the way Linux handles strings? Didn't realize that, very unfortunate if true. I am running MacOS.

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.