It seems withthis model you have a 1 year or 4000 cups warranty with this.
If you are within this, then give them a call - here is the Manual if you don't have it -
I suggest you start by removing the beans in the hopper and wiping around to remove oils.
Then refill with fresh dry beans.
Plug in and set up as normal
Set to brew a standard large cup - and adjust grinder to coarse setting while grinding.
Do not adjust with grinder quiet - it must be done while rotating.
Make at least 10 cups this way at the coarse setting.
I think what has happened is that damp beans (frozen or cold) have entered the unit and caused the coffee to gum up at the top of the burr.
This will just push fresh beans out of the way instead of starting to grind them.
If you use dry (light loast) beans, it doesn't seem to happen as much.
Just ake sure you refrigerate most of your stocks, but keep a small stock at room temperature in an airtight tin to prevent this kind of thing.
You can actually push down on the bean stack slightly with a wooden object while the grinder is running if nothing moves on the coarse setting to get things moving.