I'm at my wit's end. I had already watched the installation videos, and installing goes perfectly—the orange carrier frame for the CPU fits neatly in the black rails, everything goes down and clicks into place, but the torx screws won't thread at all. There appears to be a 0.5 to 1 mm difference in clearance compared to the PnP cap and dummy carrier frame that came with the motherboard. Nothing looks bent or out of place. This height difference is preventing the short torx screws from engaging with the threads at all.
If I take out the CPU with orange carrier frame and re-insert the PnP cap and dummy carrier frame supplied with the motherboard, the torx screws thread normally. I've gone back and forth between the dummy ones and the CPU multiple times, and every time, the CPU won't thread, but the dummy ones thread perfectly.
ASUS and AMD support are clueless.