Hi and welcome to the Chiari forum.
Surgery for Chiari is not a fix or cure, it is done to restore CSF flow and slow progression of symptoms....so it is very possible to have symptoms after having surgery. Some possible reasons are scare tissue causing yet another CSF obstruction....so it is imparitive that you see your Dr to see why you have the new symptoms. It is also possible it is from a comorbid condition that accompanies Chiari.....so do talk with your Dr and let us know what you find out.