B787 and B747 unlandable

No mate, that’s not the thing, the plane doesn’t stall, the plane gets perfectly well to the head of the runway but doesn’t flare, doesn’t wanna lift the nose neither manually nor auto land, instead of that, like 50 or 40 feet before touchdown sinks the nose, lands with the front gear, jumps twice or three times and that’s all. I’ve tried everything.