It does seem to me that our shared meaning of the term cis has by no means been worked out yet. It's a new term, so not so surprising. I see it used in sensible, sober discussions of trans issues in a very neutral way, really meaning no more than 'not trans': not suffering from a significant degree of gender dysphoria or wanting to change your gender identity. And it has a clear utility in that context, providing a neutral term for 'not-trans'. But it is also clear that some think it means something more than that, containing within it the implication that you are happy with your gender identity. It doesn't help that it's a term that's used aggressively in an 'us and them' way, especially when someone is trying to explain your existence to you by calling you that, which is always pretty infuriating. Twitter has a lot to answer for in this respect, imo, and it appears that it is often there that people first hear the term cis or cisgender, rather than reading it in a considered academic article.