Address changed, newly developed

The technician does, but what about the post? I don't think they'll hand you a package with a different address on it.

Which package is he supposed to get from Telekom? Moreover, it is not even a different address, the post also knows the old address and sees on site that it is the same property. If the connection is already in the house, I see no problem. I would simply register it under the old address.