Autism and adhd assessments

Hello

I will hopefully be getting my autism assessment around February 2024 but I now believe that I might also have inattentive adhd.

I've been on the waiting list for a while so I contacted the autism assessment place (asking about when my assessment would be) and asked if they would assess me for adhd while assessing for autism. I was told that if I believe I have adhd, I should get that assessed first as they won't assess me for autism if there's a question over that.

Fearing that she would cancel my place on the waiting list, I didn't ask any further questions.

So, my questions... does anybody know why they might not assess for autism before I am assessed for adhd? And, is it likely to be a problem if I do have adhd, I am not assessed but still go for the autism assessment?

I'm a bit worried about asking my gp for a referral for adhd as it will show in my records and might lead to me being removed from the autism assessment waiting list.

Thanks in advance for any insights or advice given