This stutter occurs only on AMD GPU. To reproduce it:
Restart your laptop,
Make sure no application is using NVIDIA GPU at the moment,
Click on wifi/speaker/battery icon on your taskbar.
This should be a consistent 3/3 repro that will make your laptop lag for about half a second.
My other stuttering vids and repro steps:
• Lenovo Legion 5 stuttery when on battery a...
• Lenovo Legion 5 stuttery when on battery a...