New front Shock aren’t tight inside strut mount

I recent purchased a set of Kimpex Pro-Gold Nitro-Gas shocks. When i install them into the strut mount and tighten it down, I doesnt stay tight inside the mount and i can pull them out. I also notice the same issues with the RubberDown Customs plug that i installed into the bottom of the strut mount. Im and doing a lift with the new suspension setup.