High CPU usage by "system" process while playing Apex Legends.

The "System" process constantly loads the CPU while playing, causing performance issues. It takes up 6-25% of the CPU all the time. I've searched for information and tried various solutions, but nothing has helped. I haven't been able to play the game for a month because of this issue, and many others have too.

I've tried reinstalling Windows, trying different Windows builds from Windows 11 23H3 to 25H2.
I've also tried reinstalling drivers to newer/older versions, including the network card drivers, the video card driver, and the sound driver, but none of this has solved the problem.