The one on the right is not.
So, I added a 100% default on the left to see if it made a difference.
Apparently not.
I have been playing with the Embarcadero demo in C:\Users\Public\Documents\Embarcadero\Studio\21.0\Samples\Object Pascal\VCL\Titlebar\TitlebarPanel\TitlebarPanelDemo.dproj and a plain TAdvEdit, and I get the same issues.