Universal credit child care

[user34632]

I have asked but still waiting for a response so hoping others on here who might claim UC can explain.
Basically child care for the assessment period was £600. I did the entitled to calculator so thought I have we had a good estimation and in the calculator it took into account the £600. However just had our actual UC amount which is £60 less as they put our childcare fees as £435. Is this right? I know £60 difference to some people may not sound a lot but it's crippling us as the minute.

They will pay 85% which should put it at £510 but assessment days can latter. Eg if you assessment period is from the 13th- 12th but childcare covers the 18th- 17th those extra days would be added onto next month’s payment.