I don’t believe it is always executive function issues - says the person who was very similar academically to the OP’s daughter in high school. Some times it is just what it is - lack of interest in stuff that’s not interesting, maybe a bit of laziness, not a rule follower, maybe a little stubbornness, not placing a high emphasis on pleasing others through grades. It often doesn’t follow students to college because in college students have a lot more choice in choosing classes that interest them.
Sure, you can test for learning issues but I don’t think one can assume that is the cause of a lackluster GPA. A mismatch between grades and test scores isn’t that unusual.