Gary Stofan
Ansys Employee

The slow graphics refersh may be caused by a 3D input device such as a spaceball, trackball or 3DConnexion device. Remove the device to confirm. Updating the driver often resolves the issue. 

Also, any sort of graphics capture program runing in the background can sometimes cause such issues. 

For licenses, make sure you are not referencing any old / invalid license servers.