Specs on screen after staingate removal

Just wondering what these specs could be, they seem to be in a long strip over the middle of the screen and only really visible on a white background, making the screen look dirty. When the screen is fully lit with colour it isn’t really noticeable..

At first I thought they could be left over from the stain gate removal I did but they would not be removed with Listerine and appear to be under the screen? Wondering if there is anyone to remove them without a screen replacement?