Clamp doesn't fit

I’ve tried twisting the smaller ring to loosen the clamp, but I can’t slide it over the cooker – it’s too narrow. I’ve even unscrewed the ring from the rest of the clamp. Has anyone else had this problem?

Mine fits properly. Have any pictures?

If the small dial is opened the entire way if you look inside it’s a circle, when you tighten it it’s like a C with the open area pushed inward - but I think that’s what you meant by the small ring.

Is there any way you can share a picture?