BRK 86RAC Defect?

I have a few BRK 86RAC smoke alarms. I was comparing each of them, and one of the alarms had something wrong with it. What was the issue with one of the alarms? There is a metal piece sticking out in the battery drawer, and The battery drawer almost closes completely without a battery, despite me trying that with a working alarm and the battery door staying open with no battery. I tried placing a battery inside the defective alarm itself, the results were either the battery would refuse to go into the battery drawer, or the battery would be ejected without the battery going in. Currently, I don’t have a connector for the alarms, so I can see if each alarm works with AC power.

A back view of the problematic alarm:

A front view of the problematic alarm:

Back view comparison with a working alarm:

Front view comparison with a working alarm:

I made a typo. I can’t see if each alarm works with AC power because I have no wiring harness for it.