So, there is large quantity of matter permeating the universe with unknown properties? Doesn't that imply that our understanding, i.e., theories/models, are in

So, there is large quantity of matter permeating the universe with unknown properties? Doesn't that imply that our understanding, i.e., theories/models, are inconsistent with observation? All the the term 'dark matter' really implies is that there are observational anomalies caused by something that could be matter-like in its nature, but which we have not observed. It isn't necessarily at all like the matter we have observed, but could be matter-like. Or we could just be wrong in our models.