Waiting 18 weeks on my first unemployment payment (update)

I was laid off as a software tester and filed right away, and I have been certifying every week. I have read a lot of threads here and could not find my exact situation. The page shows my claim as open but no payment date. What would you check first?

When I finally got through, the agent said my employer had responded late. Once that cleared, back pay came in one payment.

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.