The reason Panko doesn't speak Italian on stream is privacy. If you'll notice during Raora's debut stream she only spoke one sentence in Italian and immediately people in her chat pointed out that she was from Syracuse. This is because each major city/region in Italy speaks their own distinct dialect, to the point where movies set in certain regions of Italy have to be subtitled into "common Italian" for Italians from other regions to understand it. I think Panko has stated that she doesn't speak Italian specifically so people can't pinpoint her location based on her dialect. More recently, however, she has gone back on this, saying that everyone already knows where she is because her parents doxed her. To her surprise, when she asked her chat if they knew where she was from very few actually did. I wonder what websites she has been browsing that would give her the impression that her parents have given away her location.