Welcome back to the Wefugees Community and thank you for reaching out to us again.
First of all, I am happy to hear that you were able to join your family now!
We had a very similar question here before. I experienced that the file transfer can happen within a few days. But many immigration offices are really overloaded in these days. As my colleague also explained in his answer in the other thread, it can make sense to remind the immigration office on the transfer. I assume you are registered in Viersen already, right? As soon as you have done this, the transfer should happen automatically.
I hope this helps and please don't hesitate to get back to us with any further questions.
All the best,