Engine animations not working properly

Hi all, I'm using FSX and I've noticed my engine animations don't appear to be working correctly. By this I mean there is no 'in between'. For example, if I shut down the engines they don't 'slow down'. They get stuck on a repeating animation (which looks fast) and then when the engines have stopped they suddenly jump to the stopped animation, ie stationary fan blades etc. There's no visible slowin down of the blades. I've notices this across most of my aircraft except the PMDG NGX. This includes Wilco Evo packs, MD11X, 747X etc.

Is anyone else suffering this? I went through a full reinstall of windows today and it still hasn't resolved it. Any help?