Fisheyes are almost always either contaminated material (dust, finger prints, etc.) or old/defective vinyl. That's what this looks like to me. Does it happen on any other materials? Heat could very well help as well as it's needed for the ink to bite into the vinyl properly.
Just because the material is fresh out of the box doesn't mean it's good to go. Have had to return multiple rolls of contaminated materials from all different manufacturers.