Why does Ghostwire: Tokyo stutter and fail to load on the MSI MAG B460M MORTAR?

Running through the streets of Tokyo in Ghostwire, the screen suddenly stuttered with fatal loading lag. I first tried lowering the memory frequency blindly, which stabilized the system but caused severe frame rate loss. That was a dead end. I reseated the memory modules and adjusted the frequency from 3200MHz to 3000MHz in the BIOS, using the GamePP Resource Scheduler to manage stability. MemTest86 confirmed zero memory errors. Frame rates stabilized at 90-95 FPS, and GamePP showed memory temperature at 45-50℃. The VRM temperature is now 58-63℃.