Reflection Probe setting customBakedTexture as instance?

Hey,

I am trying to set the customBakedTexture of a reflection probe from my editor script. I get the Reflection Probe by using FindWithTag("tagname") to get the GameObject and then using GetComponent() on that GameObject. I then try to set the customBakedTexture which appears to work when looking at it with Debug.Log(probe.customBakedTexture); but when I click on the object in scene it still shows the old cubemap.

In the Unity Docs it shows that the customBakedTexture is supposed to be a reference but it seems like it is setting it as an instance.
https://docs.unity3d.com/ScriptReference/ReflectionProbe-customBakedTexture.html

Is there a fix for this besides making multiple GameObjects in scene and swapping between them?

Cheers,
Charlie