I have been having a problem with rippled sides It starts out looking smooth, but after a few hours you can see ripples. I make sure the cake is very smooth before covering with fondant. I am very meticulous and I feel like I am doing a really good job prepping the cake- but something is not right? Any advise would be greatly appreciated

Are you describing perhaps a bulge in the sides of the cake? If so, it could be the filling bulging out. Does this sound like it may be the problem?

How long are you letting the filled and crumbcoated cake rest before applying the fondant? I'm wondering if your cake may be continuing to settle after you cover it - the cake itself settles and shrinks a little in height, but the fondant doesn't shrink, so it ripples.

Do you let your cake settle overnight with some weight on top? Sometimes when you cover your fondant cake too early after frosting then the filling doesn't have time to settle. Also, do you overfill or dam your cake correctly (I use a very thick almost doughy type of buttercream to dam with). I can't really think of anything else. HTH
Fedra