Just to update this: yes, the screws of the original cooler were loosen. So it was not seated correctly.
Now I also replaced it with NH L9x65.
But still see the temperature goes up to more than 90 when just installing some apps from the zimaos app store. And also set the Fan mode to “Full mode” in BIOS.
https://community.zimaspace.com/t/zimacube-creator-pack-heat-issues/3614