Option Preferences / File Displays / Border / Align other Lister element headers with the file display border is broken.
I think that may only happen if the folder tabs are at the top. I doubt it's new in Opus 12, but we'll put it on the list to look at (I guess the headers should align with the tabs rather than the FDB).
It's ok for tree in Opus 11 (screenshot).
But not for Meta panel header.
It's not quite aligned in that screenshot either.
Yes, but both tree headers have the same height 
I find this : [url]DO11 : Align other Lister element headers with the file disp]
Ah ok, I didn't realise that's what you meant. Sometimes a red arrow isn't enough of a description 
That'll be addressed in 12.0.8 (for the Utility panel also).
Not fully solved in 12.0.8.
If you open panel (meta or viewer) first then enable dual mode (horizontal), tree header have not the good size. And if you close panel, tree header is resize.
Can we see a screenshot of that?
It should use the file display border height.
Thank you! I've fixed that for the next beta.