How long for truck manifest trade portal approval?

Hi guys,

I have made my first few manifests with BOL's and successfully submitted them to the CBP (USA). That was a few days ago and I have not heard if they have been approved by customs or anything like that...I was told it usually takes between 30 mins-1hr to be approved. Did I do something wrong? Or maybe I'm misunderstanding how this works exactly.

Thank you