Or what would that be called? Pretty much the same things that would usually be considered ableism, but when there’s not a recognised disability involved but just health issue/s (which could be “disabling”).
For example, not believing someone about their health issue, dismissing it or refusing to believe that it impacts their ability to function or can be a valid excuse for things (often solely on the basis that it’s not a recognised disability), blaming someone’s health issue on different things they aren’t caused by (and trying to attribute it to the person’s behaviour as if it’s their fault), and/or claiming that their opinions can’t be taken seriously due to their health problem
Would it be called health-based discrimination or something (despite somewhat mimicking the same mentalities as ableism)?
Ableism is so ingrained in our society that folks have trouble even recognizing it. OP is absolutely experiencing ableism, being dismissed and treated differently because of their health issues, recognized and intentional or not, is ableism.
Your example is a very legal perspective of ableism that barely scratches the surface of ableism and makes it difficult to address wider impacts. This is a similar thinking to racism only being legal segregation and the KKK, when it shows up in everyday life in far broader ways.