aio Help with first aio install

[Titaniumx24x]

Hey guys just built a new rig with a ryzen 7 5800X3D and wanted to try an aio liquid cooler(corsair h115i elite capellix) I've always been scared to try one due to water being involved but anyways when I put the standoffs in the mobo and into the backplate for mounting pump/pump screws 3 out of the 4 standoffs were just kinda spinning in the hole so I tried to mount the pump anyway and none of those 3 screws would tighten only one is fully tightened so I presume the cpu isn't getting adequate contact with pump heatsink. Temps aren't great idleing around 60-70 degrees and hitting 80-90 degrees in games. I'm wondering if I l need to buy a new mobo backplate or if the aio standoffs are just hecked