Is the animation of your bump map occurring inside a precomp or is it effects applied to a layer in your main comp? You have to precompose if you're trying to use effects like Fractal Noise on a layer.
If that's not the issue, we're going to need a lot more information in order to help you.
Version number of AE CC 2015 that you're using, hardware specs, how EXACTLY you have your project set up, etc. screenshots would be really useful.