I had this exact issue last week, I ended up just putting child tax account as the name and even though it said it didn’t match it still went through!
Gov childcare
We had massive issues with this! We had to use “NS&I TFC CUSTOMER” Luckily a few friends of ours had sat on hold to HMRC to ask so we didn’t have to
I still use what the system says to use tbh, I’ve never had an issue and the nursery always gets the payment.
I think i just put tax free childcare and its worked just fine and the money has gone in
I think it’s the reference number x