Mutoh 1624x White Dots Printing Solid Color

Hey,
So I recently had to color match a dark blue for a company, I printed a solid panel for them. However straight off the printer there were small white dots in the print, also what appeared to be discolorations. I printed the same panel twice, and same results both times. I've printed other solid colors since then, and had no issues with white dots. Any ideas?

Thanks!!