Outline introducing lighting changes to my scene

I have a piece of code that using the outline conditionally as shown below.

      {highlight ? (
        <EffectComposer multisampling={8} autoClear={false}>
          <Outline
            pulseSpeed={2}
            selection={[myMesh2]}
            visibleEdgeColor="white"
            edgeStrength={100}
            width={1000}
          />
        </EffectComposer>
      ) : null}

The outline behaviour works correctly but it's introuducing weird lighting behaviours. The first image is before it triggers, the second image is while it's active and the third is disabled after being triggered at least once. Does anybody know what the cause of this is? This is the only post processing effect that's being used.

Reproduce the conditional EffectComposer and Outline snippet, then compare lighting before activation, while active, and after disabling it using the attached images as reference. Done means the cause of the lighting change is isolated and the scene lighting remains consistent when the effect is toggled.