Are asexual people straight?
Asexuality encompasses a broad spectrum. For some kinds of asexuality (e.g. hetero-demisexual, or heteroromantic-ace) some asexuals consider themselves to be straight, often because for them personally they don't see any difference between their social dynamics and that of heterosexuals. However, it's important to remember that even for these kinds of asexual, sexuality can have a large impact on different areas of a person's life, to the point where they may identify more with the non-straight label.
In any case, "straightness" isn't really a strict category, it's more of a loose social concept around what is considered to be normative. Ultimately it's not helpful to lump all asexual people into boxes like straight or non-straight: that would be ignoring the lived-experience of many asexuals either way.