It's also possible to offset the UVs by one unit in the UVs setting of the Array modifier: Same applies when using the mirror modifier. For instances/duplicates, UVWarp modifier can be used to offset UVs.
THANKS¡¡ it just was the overlaping of the tentacles in the low UVs. I had sculpted just one of them and i applyed the array modifier after making UVs to got them all in one place, because of that some tentacles have a "nothing" hight map to bake (tentacles that i have no sculpted = empty space = black bake). Just if…