I test drove a Nissan Juke automatic recently and the gearbox felt very different to what I’m used to. The revs stayed high and it felt like it wasn’t changing gears normally. I know it’s a CVT but I don’t know what’s considered normal behaviour on the Nissan Juke. There was also a slight whining noise. Is this just how they are or signs of a gearbox issue starting to show?

The CVT does sound strange when driving compared to a manual transmission.
But if you can find another just to test drive and make a comparison to satisfy yourself as to whether it is normal or not.