Psych NP offered Strattera but said it's too early to diagnose ADHD — is this normal?

I scheduled an appointment because I’ve been struggling with concentration, completing tasks, frequent daydreaming, and procrastination for a long time. A few physicians in my family mentioned that these symptoms sound consistent with ADHD. They technically could prescribe medication, but they advised against it because it can raise questions with medical boards about why an anesthesiologist would be prescribing psychiatric medication, and suggested I see a psychiatrist instead.

I ended up being scheduled with a psychiatric NP. During the appointment, I explained my symptoms, and he offered to start me on Strattera. I told him I was diagnosed as a child. Afterward, I messaged asking if he could write a letter confirming an ADHD diagnosis since my school offers accommodations.

He responded, saying he’s not comfortable making a diagnosis yet and that it’s too early to tell, and that we can discuss it more at the next appointment.

I’m feeling a bit frustrated because I have important exams coming up this week and was hoping to submit documentation for accommodations.

Is it normal for providers to wait before formally diagnosing ADHD even if they’re willing to start medication?

Also, is it common for a psychiatrist to diagnose ADHD in a single visit, or does it usually take multiple appointments?