This has been already discussed in another thread.
We really can't fix it entirely, because by sheer misfortune, a seam in the MS tiles system runs exactly in that point so, even if we put a flattening polygon (which we obviously already HAVE), the polygon gets splitted in two over the dividing line between the two tiles and, for some reason, a flattening polygon that has been splitted by the sim this way, is not flat as we made it.
The only conceivable fix would flatten the WHOLE airport to the same height (some developers use this trick, we also did when converting old airports from P3D, but not LSZH), but that would cause a far worse drop in realism, because all runways ends would then at the same height, instead of the different heights they are reported on charts, messing your ILS approach (for those that care) more than that small bump.
