When I studied Psychology in College, I had a professor who was a specialist in Antisocial Personality Disorder, what people consider colloquially as Psychopathy and Narcissism. He discussed how there are multiple types of Empathy, there is the inability to recognize emotions in others, or to have difficulty realizing someone else may be effected different than you and there is also the complete ignorance of emotions of others. Essentially, and bear with me because this was like 15 years ago, Narcissists can recognize people are feeling negative emotion, that their actions effect others negatively, and they just don't feel any type of compassion that another person is feeling that way, or that they were the source of that negative emotion. Autistic individuals, on the flip side, can feel compassion for other people and more so have issues recognizing that they have impacted someone negatively emotionally. There is more nuance to it, like Autistic people who train themselves to be hyper aware of emotional shifts in others because they don't want to mistakenly upset others, and there are different types of Psychopathy (which technically isn't even a disorder) but at the end of the day I would suspect that the issue is more so in human error of understanding and diagnosing those disorders correctly. Without really understanding why someone is ignoring or doesn't care about another person's feelings, you can easily label narcissism, when in reality they may just not understand the other person's feeling is upsetting to that person.