BUG. When mirrored window is open, (win10 or 11) frame loss and stuttering

So seems this has been going on for a while.

Reproducible across multiple platforms. When mirrored window is open on monitor or TV we see significant jutter , skipping and spikes in GPU frametimes. Generally most noticeable when under loaded or high GPU usage.

Only fix is either turn off monitor. or minimize window.