Lightroom 6.14 Tethering doesn't work properly

Dear to All,

for a photographer I had to set up a new computer with Windows 11.

We had installed Lightroom Classic Version 6.14, because all had worked on the old computer.

The tethering function is not working with the Nikon D750.

The camera is recognized in lightroom and can be triggered from lightroom, but the picture will not transfered to lightroom.

What ist going wrong?

Thanks for your help!

Best regards

Peter