HP Proliant DL380 G7 Power Supply Unit problem

[JoeyHPE]

Hi there forum, I really don't know where to ask this, so i'll just do it here.

So I have two PSUs for HP Proliant DL380 G7, both exactly the same:

https://photos.app.goo.gl/9qW7neHrE1Ibptn83

One of them doesn't want to fit in any of the two PSU slots. It just won't go all the way in (it won't snap). I compared them both carefully and nothing seems to be different or bent even the slightest. The one that doesn't "fit in" has this missing bronze thing, that I pointed out with red arrow on the picture linked above. Speaking of this bronze thing, I also want to know what is the purpose of it? Is it needed?

By the way, model of the PSU is: HSTNS-PL14 (460W)