Notice of correction DLA

Hi I recently won a DLA tribunal for my daughter on the 12th January . DLA have awarded this but have issued a notice of correction back to the judge to see if we are going to have any back pay
how long does this process take? Are we likely to have any backpay? The appeal letter states 
1. The appeal is aloud
2. The descion made by the responded on 21/7/18 has been set aside 
3. Awarded higher rate care allowance 
4. Awarded higher rate mobility allowance