I'have just found that if you change the height of the cyan brick in the wall example of the documentation, the position of the brick is wrong.
\begin{wall}
\wallbrick[color=blue]{2}{1}
\wallbrick[color=red]{1}{1}
\addtocounter{brickx}{1}
\wallbrick[color=orange]{1}{1}
\newrow
\addtocounter{brickx}{1}{1}
\wallbrick[color=cyan,brickheight=0.3]{4}{1}
\end{wall}
I suspect the solution would be to use a "default height" to compute the "z-coordinate" of the brick, not the actual brick's height.
Thought I didn't checked if it would complicate the code very much.