Windows Server 2025 Hyper-V GPU-P not working

Is a environment for testing like in microsoft article
Partitionierung und Zuweisung von GPUs zu einer virtuellen Maschine in Hyper-V | Microsoft Learn

The other environment (We have three of this DL380 G11 servers) we want to use GPU DDA for some Remote Desktop Hosts. But here we also have problems. We can see our GPU in VM device manager. But when we make a RDP session it only uses Microsoft BasicDisplay Driver. Although we configured the GPO’s to use Hardwaregraphics Card.
Which driver do I have to use in VM for this scenario?