Hey there. Since typ works, this can be a bug or an oversight. I’d expect it to just work like in document or on forum. Though it might be because the same problem exists in repositories/issue trackers, i.e., only typ/markup mode is supported.
Odd. Sounds like color scheme is missing, if it’s per-language…or more like “CSS class” dependent. Probably better to document this in the issue tracker. I’d expect it to not be parsed/recognized nor highlighted, or both. Surprised that it’s something in between.