Something surprising to me that I read online and confirmed with my psychologist:
The "restricted interests" part of autism primarily describes the intensity of special interests, it does not refer to having difficulty caring about / giving attention to topics outside of those interests.
The latter is actually considered to be a symptom of the ADHD "interest-based nervous system".
IMO "restricted interests" is a pretty misleading name.
@charlotte @Misofist iirc it ysed to be even worse ("elective mutism")