Welcome, wmom!
Sometimes ADHD (especially primarily inattentive) is more subtle in higher cognitive kiddos, because they're a lot better at masking, or at using compensatory strategies to power their way through some of the tests used. But it's also possible that something else is in play. We don't have much to work with in terms of data at this moment, but what you describe could also result from an auditory processing disorder, especially with difficulty following multistep directions and comprehending oral language. One-sentence answers also raise questions regarding expressive language delays. It can be hard to tease out all the possible factors, especially depending on the nature of the evaluation data you obtained.
There are also other executive dysfunctions that don't meet ADHD diagnostic criteria. But just because they don't meet criteria doesn't mean they don't affect one. If you feel comfortable posting, what instruments did they use? (If not publicly, you can pm me; just let me know you did so, or ask me to pm you, as my inbox is kind of full!)