Matt Berry played Douglas Reynholm who was the central character in that controversial transphobic IT crowd episode. Despite that, I gave him the benefit of the doubt because it was the 2000s and the topic of trans rights was virtually non-existent in mainstream discourse. It was also before Graham Linehan outed himself as a raging bigot. I also absolutely love that show in general.
I don't know if Matt has ever talked about his views on trans people, but him appearing on this is not a good sign, and very disappointing for me as someone who is a fan of his work.