Missing "Reset Custom Segments" button in Curtain Wall Scheme

[Emilio]

I am working with a basic curtain wall and have edited a few mulls in the 3D edit window. Isn't there supposed to be a "Reset Custom Segments" button that reverts the curtainwall back to the base mull scheme? I have seen the button is other posts, but don't seem to have it on my interface.

Thanks in advance for any help

My interface:

Image of missing button:

Operating system used: Windows 5003 USA Full