Why does Indiana Jones and the Great Circle stutter on RX 9060 XT?

I was exploring ancient ruins when frame times suddenly spiked from 8ms to 32ms, making every turn feel sluggish and breaking my immersion. I tried enabling Enhanced Sync in the driver panel, but the stuttering persisted and it introduced a brutal 45ms input lag, making the game feel like walking through mud. I then used the GamePP Resource Scheduler to set the game process to Real-time priority and restricted background VRAM to 500MB. GPU temperature stabilized at 64-71℃ per GPU-Z, and frame times converged to 6-12ms verified by GamePP Tool, while VRAM load hit 74-86% per AIDA64.