Okura Yusoki A Series Manual page 206

13.1.6.3.5. Mate (2x2) brick by center line
OXPA fails in sometimes mating, if pattern is (2x2) brick.
The line of reversing axis of (2x2) brick pattern is to be specified with [Hrz center] or
[Vrt center] at [Mate (2x2) brick by].
Example1: (2x2) brick pattern laid side by side
Example2: (2x2) brick pattern laid side by side the other direction
13-16
OXPA
sometimes fails.