I got an everlasting problem with a aerated autoclaved concrete (also known as "Gasbeton") wall: there's a crack that seems to split the upper half from the bottom half of the wall.
I tried several time to fix it, either with the proper aerated autoclaved concrete putty and with stucco but, after some days, the crack comes back again.
Any idea on how to fix it for good?
EDIT: The wall is made of AAC blocks (as bricks), I have access to both sides and is an interior wall: basically it divides one former big room in two smaller rooms (kitchen and bedroom).