Is the file you’re importing mono or stereo? Do you have anything else running at the same time as Cubase? When is the last time you cleared your temp folder? Have you defragged your computer lately? Not sure any of this will help but it won’t hurt. 
Is the file you’re importing mono or stereo? Do you have anything else running at the same time as Cubase? When is the last time you cleared your temp folder? Have you defragged your computer lately? Not sure any of this will help but it won’t hurt.