I've included a screen grab of the situation because it's easier to see what is happening by watching it.
I don't know why I can copy style attributes between objects for some button bars but not for other button bars.
In the video I select a button segment and try to copy attributes. That fails. You can see that the Style Paste button remains dim. I then select a different button segment. I am now able to copy/paste attributes. The Style Paste button becomes active as soon as I click the Style Copy button. Moving back to the first button, I click the Style Copy button and the Style Paste button dims.
Does anyone know what is causing the two buttons to have different behaviour?