> That suggests ADHD people lose track of where they left off when performing several tasks

Not quite. At least not for me. My problem is hyperfocus. If I switch tasks I might go down a rabbit hole and forget to change back. It is similar to being distracted, except the distraction can still be legitimate work stuff. My focus is like a freight train, it's hard to change tracks

Which can seem like an attention problem when you're trying to change me from focused code mode to "jump on a call" mode