Or what would that be called?
For example, not believing someone about their health issue, 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, and/or claiming that their opinions can’t be taken seriously due to their health problem?
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.