Trackpad click not working

Hi there!

I bought a trackpad from ifixit for a MacBook Pro 13" Unibody Mid 2012 as my old one was lacking sensitivity on the right hand side and couldn't really work it out which was very annoying for the type of things I do.

I replaced it by myself but while it moves, and there is a physical click, it doesn't work. So I can drag it around but that's all.

When installing my old trackpad, works fine (besides the sensitivity issue), tried to swap them around a couple of times, loosen the screws, and nothing happened.

Any ideias or ways to fix it? It probably is a hardware issue, anything I can do or it's just a faulty trackpad?

I bought it as new, but it has some scratches in the lower surface...

Battery is not swollen.

Thanks