Superscript character not exported to XLIFF


I'm using Passolo professional

My dll source file contains a character for square millimeters, which is displayed in Passolo as folows:

Text properties editor:

string overview editor:


This character is not exported to xlif, i.e. not translated / reimported properly (just left out it seems:

this is my current parser setting:

Does anyone know what kind of character that is and whether it's an issue of the source file's encoding or parsing or... Where should I start investigating? ;-)

(BTW: I used a freeware tool to look into the DLL file but even there I don't see the superscript 2., just not displayed...)

Thank you! :-)