I just installed one and that puzzled me at first.
It's important to have that push back because that keeps the cooler firm against the CPU
Just don't push so hard as to flex the MB. Also, make sure you used the correct standoffs because they supply some for Intel and some for AMD.
I used the dark tallest ones (not the bright chrome ones) for my AND AM4 cpu.
I think Intel uses the shorter, bright chrome ones.