Hi. Im trying to install the corsair h100i v2 on to an asus z270g board. The issue that i have is that the back plate has a bit of give once the standoff screws are in place. The space between the board and standoff screws is about 3mm. And i can push the bracket back and forth. My concern is that once the cooling block is in place. There wont be any contact with the cpu.
I had the exact issue with my IX hero (similar to your board), once you installed the cooling block it actually all fits fine, dont worry !