Hey, I definitely feel you that inattentive ADHD is under-diagnosed in both men and women. Hell, ADHD is general is under-diagnosed!
I do want to mention, in case you aren't aware, that the difference between men and women being diagnosed with ADHD is dramatic:
Males are generally more likely to be diagnosed with ADHD than females, with a male to female ratio of approximately 4:1 in community samples.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3101894/#S5title
When we talk about the way women are under-diagnosed, it's a very unique phenomenon because most women have experienced gender bias at hospitals.