door jam spring clip

Hello all,
The spring clip that the door pin presses into on my lower door was spread open to the point where the fit was very loose. I unscrewed the spring clip and pressed the clip back to it's original shape which did the trick to secure the door snugly. I thought all was fixed, and closed up the trailer. I opened our trailer a few days later, and the clip was spread apart again. Any thoughts as to what may be going on? Might I need a new clip? Your thoughts and knowledge would be greatly appreciated.

Thanks,

Bruce