Why does Warhammer 40,000: Space Marine 2 stutter during combat?

Summoning units caused painful stutters. I closed background apps, but the lag persisted. I used GamePP NVMe Queue Depth Configuration to increase the depth from 512 to 1024. CrystalDiskMark confirmed the read speed jumped from 3200MB/s to 3500MB/s, and loading times dropped to 5 seconds, making the combat flow perfectly smooth.