No tracking for 10 days

Hello, I sold a bag and the buyer requested authentication. I sent it 11 days ago and the tracking hasn’t updated it since the day after I sent it. Two months ago I also sold an item that was sent to the same authentication center (in Germany) and it was much faster. The buyer is starting to worry and I’m wondering if I’ll get the money if this is truly lost. I’ve read the terms and conditions but it’s not super clear. Would appreciate any insight you all may have ! Shipper is DPD which is owned by the French La Poste.