SFE saying DWP national insurance number came back as invalid but it is not??

Really stressed as I am unable to upload my NINO to student finance without it saying there is a problem, I've already waited weeks to update my details to get my NINO, tried to submit it to SFE to finish off my application but running into some issues and have no idea how to fix this - I've contacted SFE but still unsure what to do, scared there will be delays now even though my application was approved a while ago, does anyone know what route to take to fix this, everything is a bit unclear!