ok – did some trouble shooting.
no squeal when its just my laptop plugged in.
Squeal if my laptop is also plugged into my hub which allows me to connect to many other things – including my 32″ screen and charges my computer…
No squeal if I plug the usb into the hub instead of directly to my laptop. So maybe a weird charging/ground loop squeal (sounds a lot like when you use non isolated power supplies and mix analogue and digital stomp boxes on them -like daisy chaining)