Hi @laurayuan ,
Don’t know the answer but according to the [https://www.bequiet.com/en/cpucooler/1659|installation guide - see AM4 installation] (click on Documents > manual) did you remove the plastic retainers as described in the guide? Not quite sure if this is what you meant when you said “I put the spacers out…….”
Here’s the quote from the guide:
“To permit mounting of the cooler please remove both the plastic retainers of the AMD retention module. The factory fitted backplate affixed to the rear side of the motherboard will be needed for subsequent installation of the cooler.”
If you have then, try [https://www.bequiet.com/en/contact/service|contacting] the manufacturer’s support line for advice.