Actually I do have a suggestion; dull coat, in multiple layers acts as gloss coat. One coat of dull coat should be used and no more. If you didn't shake the can up very, very well and you put the first coat on too thick it will come out shiny. Any attempts to dull it down with more dull coat from there will only make it shinier. I suggest repriming and repainting, or just repainting. Contrary to popular belief you can paint over dull and gloss varnishes with acrylics.
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