In early October, Assassin's Creed Shadows gamers noticed substantial frame rate drops following the monthly Windows 11 KB5066835 update. This issue was later addressed by NVIDIA in a driver update, but Digital Foundry did some more rigorous analysis than the Steam community who initially brought the issue to light and confirmed that Microsoft was indeed to blame. During its testing of an unpatched version of the problematic Windows 11 update, the publication found performance degradation on the order of 33-50%+. Testing also confirmed that there were performance regressions in Counter-Strike 2, although neither NVIDIA nor Microsoft have shared any information about what other games were affected by the performance issues.

Testing Assassin's Creed Shadows at 4K with max settings and DLSS set to Quality on an AMD Ryzen 7800X3D and an NVIDIA GeForce RTX 5090 resulted in frame rates of FPS before the NVIDIA GeForce patch and 72 FPS after the driver update. The investigation was unable to yield any conclusive evidence about the cause of the performance degradation, but speculation points to either a driver vulnerability that was patched out of Windows in the update or some sort of driver conflict induced by Microsoft in the update process.