My son was deemed the king of chemistry by his AP chem teacher, nailing every test and doing very very well… Except in thermodynamics and IMF. Those he had trouble with. He got a 5 on the AP test.
You don’t have to be an expert in all areas, in order to do well on the AP test. Move on and do well in the rest of the class. And yes, according to my kid the class was hard and took a lot of work.