Anyone unexplained now explained?

We just failed our 3rd medication IUI.

It all looked perfect, and all the nurses were optimistic. Over 100million motile sperm, 2 mature follicles, optimal lining and great timing yielded a BFN.

My questions are for anyone that has experienced Unexplained Infertility who went on to discover their cause.

What were you diagnosed with?

How did they find it?

Is there a corrective procedure or product?

Have you overcome infertility?

Thank you.

Just trying to figure out my next approach.