2014 s60 trans overheats above 70 MPH

[azureblue]

Daughter is out on the road, and the car' transmission overheats and won't accelerate above 70 MPH. She says the car runs fine if she keeps it under 70. She had the trans flushed by a Volvo shop before the trip. She is headed back to the shop now - at least she was about an hour away from the shop when the issue started. Any idea? Transmission damage?

Thanks

R