Hello @gaschka,
Thank you for reaching out to us. Yes, this is an encoding issue. In general, Unicode is supported by the Python to C++ bindings, as you can see, French, German, and Turkish diacritics are all correctly transported, as well as Chinese characters.
5bfdbc74-f638-4fd8-8df9-2b95479b233b-image.png
But all these are part of the Basic Multilingual Plane (BMP) while the emojis are part of the Supplementary Multilingual Plane (SMP) of the Unicode table. It could either be that there is something not implemented or some bits get chopped off while data is sent to the C++ layer. I don't really know, the person who is responsible for the Python bindings, @m_adam, is on vacation. I will ask him once he is back, as I too would be guessing what is happening here exactly.
Cheers,
Ferdinand