Hi! So there might be multiple reasons that this is happening.
Check for the following:
Your top conical burr has been placed in the device correctly. You should have it flat side down.
There is no compacted coffee grounds in the grinding chamber. Sometimes excess grinds can get stuck in the conical burrs or in the crevices of the grinding chamber. If you find this to be the problem, gently clean it out with a brush or paper towel.