Uc packpay question

I had a journal message on 21/04 saying I've been awarded LCWRA. I've had continuous fit notes with no gaps since the start of my Universal Credit claim on 18 August, with my first fit note backdated to 1 April.

I'm trying to work out whether I'm due any LCWRA backpay, and if so, roughly when I should receive it.

Fit notes:
- 01/04 – 01/10
- 01/09 – 03/11
- 03/11 – 01/12
- 01/12 – 29/12
- 30/12 – 03/03
- 03/03 – 06/05

Assessment periods:
- 18/08 – 17/09
- 18/09 – 17/10
- 18/10 – 17/11
- 18/11 – 17/12
- 18/12 – 17/01
- 18/01 – 17/02
- 18/02 – 17/03
- 18/03 – 17/04
- 18/04 – 17/05

Does anyone know which assessment period LCWRA should be paid from, and when any backpay is usually issued after the decision?

Thanks.