[Matrixbeast]

I don't see the issue with using the character's name in place of "Sempai."
It seems like having a problem with subbers leaving out "-San" and etc.
It's a term that we don't have a direct English equivalent, HOWEVER, it's also directly referring to a person, so rather than leaving a word untranslated and flipping off viewers who don't speak Japanese, they used the closest approximation, which would be to use the character's name in place of it.

I'm heavily biased against leaving in Japanese words thanks to my anime watching days, which would leave stuff like "Onii-San, Daijoubu, Hikkikomori (Fuck whoever decided this was a common enough word to leave untranslated, btw), etc" untranslated.