Should I include "visiting" in my visiting assistant professor, or just call myself assistant professor? I have a visiting assistant professor (VAP) position, and that is how I list myself on academic sites like ResearchGate and LinkedIn. I have on more than one occasion, however, seen that people in VAPs will list themselves only as "assistant professor," in things like email signatures or on websites.

Is this acceptable? Because of course if that is acceptable or expected to some degree, I would probably do the same to make myself look better at surface level. My first impression is honestly just that it is just upselling for the sake of students and other correspondents though, and my guess is that it would make a bad impression to do so and have search committees seeing that on a website or whatever after they get your CV with the VAP in an application.

Is this a wrong impression or should I update all my online statuses?

[Edit: just to clarify, I was not asking for permission to lie about my status. I have never altered my title nor really planned to, but given what I observed I felt it was still a question that could be clarified. As you might expect, the observations I was talking about come from junior faculty colleagues at my institution, so I was unsure of the typicality of such behavior.]
I agree with you.  People expect websites, email signatures, etc, to have accurate job titles, and there is a major qualitative difference between "Visiting Assistant Professor" and "Assistant Professor".  Dropping the "Visiting" unintentionally is careless, and intentionally dropping it to "upsell" (i.e. mislead) is unethical.

(You might as well say, as long as you're dropping words, why not just make yourself a full "Professor"?)