Stuck on identity verification for my claim - 14 months and counting

My claim has been on hold for 8 weeks because the identity check will not accept my documents. Any experience at all would help. I tried the online option twice and the app crashed. What finally worked for you?

Check the list of accepted documents on the official site. Mine included things I did not expect, like a passport card.

Write down the date and reference number each time you try. They asked for it when I finally got through.