Taking Control button does not appear unless part inspector window is closed and re-opened

Before click it, be sure to mute your speaker: A lot of noise incoming
https://youtu.be/KT9tpw6-BJc

You can see that I have 2 control cores in my craft. I pinned inspection windows of each. Once I take control over another control core, the original core should have "Take control" button. It doesn't.