XD 45 Problem

I recently bought a used 4" XD 45. While shooting it yesterday,the slide locked halfway open after it fired. Slide won't budge. I called Springfield,and they sent a shipping label. I'm sending it back,but wondering if any of you might know what happened. Everything else looks normal, but the slide's locked halfway open.

Is there a donut shaped ring somewhere in the barrel?

Is there a donut shaped ring somewhere in the barrel?
No, I can't find a ring in the barrel. What is this ring?

He means a bulged barrel. There isn't much that can bind up an xd. Is there a partially chambered round?

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I can't see one,but think I can feel one with a dowel. The grip safety is stuck in too.

Can you take a pic. I can't imagine what it is but it sounds like a link or something broke or bent.

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