Both are Creates horizontal framed glass pane.

I have run into the same issue with vanilla spruce stairs and connected glass panes.

Oh i have long been aware of this, but i didn't yet find a reasonable way of resolving this issue without breaking too many other create addons or create itself. Which is why this issue is staying open, until i learn/simi implements a way to achieve that by reasonable means.
Of course, if you have any good ideas, you can PR a fix and i'll happily merge it.

Nah, sorry, I'm just a whiney user :D

If you use the connecting glass from the Connected Glass mod, it also doesn't visually connect. It does work though, so that's nice.