In Ghosts (2020), two episodes previously, it was established that Nandor no longer understands his native language, yet at the beginning of this episode he's comfortably reading a letter from his parents, which would logically be in this native language.
When Guillermo comes home covered in blood, the vampires think he is wearing tie-dye. They're vampires and should have reacted to the smell of blood all over him, however Guillermo is shown killing multiple vampires and is covered vampire blood, which apparently smells normal enough to other vampires that they don't question it.
When Nandor is trying to unlock the laptop, the Mac error chime is heard, but he is not using a Mac.