How many miles ?
It's probably just worn out....... Its a common issue for folks that are "In-tune" with their suspension....... You have several options.... Ive read there are people that can rebuild your stock. You can get a 'take off' shock......... or you can look into new or used 'aftermarket' equipment that was designed and developed to be rebuilt anytime needed.
The aftermarket set is the best. Getting it set up for YOU, what you carry & how you ride will give you the best experience........