KB5067931 and KB5067036 severely impacted Gaming Peformance

There seems to be a news story about this.

Task Manager Bug in Windows 11 Leads to Performance Loss:

Microsoft has officially identified a bug in Windows 11 that can negatively impact performance in versions 24H2 and 25H2. The issue, which affects Task Manager, prevents the program from closing properly. When users exit Task Manager, its process, taskmgr.exe, sometimes remains running in the background. Over time, multiple instances accumulate, consuming memory and potentially reducing system responsiveness. The problem began appearing after users installed the optional cumulative update KB5067036. This update is not delivered automatically through Windows Update but was downloaded by many users seeking new features, such as Start menu customization, the ability to disable content recommendations, and a redesigned battery icon. Unfortunately, it also introduced an unintended side effect.

According to Microsoft, the issue causes Task Manager to fail to terminate after being closed. The previous instance stays active invisibly, even when the window disappears from view. When the user opens Task Manager again, a new process starts while the old one remains stuck in memory. As more sessions accumulate, the total memory usage can climb significantly.

While each individual Task Manager process uses about 20 MB of RAM, frequent use or long uptime can multiply this number. Dozens of orphaned processes may remain active, eventually degrading performance or stability. Systems that remain powered on for long periods or that frequently monitor system activity are most affected.

Although the bug does not pose a risk of data loss or crashes, it can cause noticeable slowdowns, especially on machines with limited RAM. Users may also see reduced performance in multitasking scenarios, as memory resources are tied up by redundant Task Manager instances.

Microsoft has acknowledged the issue publicly and confirmed that a fix is under development. The company has not specified an exact release date but stated that an update will be issued “in the coming days.”

In the meantime, affected users can mitigate the problem by manually closing all taskmgr.exe processes. This can be done either through Task Manager itself—by ending each duplicate entry—or by running the taskkill /F /IM taskmgr.exe command in Windows Terminal or Command Prompt. After all instances are closed, Task Manager will behave normally until the issue reappears.

Source: https://www.guru3d.com/story/task-manager-bug-in-windows-11-leads-to-performance-loss/