After a month of trial and error, I slowly found some tricks in treating the bread starter and dough. Also after some good advices from Mr Martin of White Bricks Oven.
So I have a better ciabata today.
Like my pottery teacher said, work with the clay and not work on the clay. I guess it goes the same to the bread.
My fault as I let them stick to the plate before sending them into boiling water. ;P