Question small dot of all colors in the print

hello sorry for my bad english, i have a small A4 uv printer with pump function to mix white, i have a problem when printing on colors like "brown, purple, gray etc." i have small point of all the colors while on the primary colors "red black etc .. I have no problem I have been having this machine for 1 month and the after-sales service cannot solve my problem. Do you have any idea? ? thank you so much !

https://ibb.co/nR9bkNJ here is the link to an example of my problem thank you very much

 

Thank you very much for your answer you help me a lot !, I use this printer ( https://ibb.co/LxZ7nRL ) I do not know its name it has epson L800 printheads

for the ink I buy it at a Polish wholesale here are the characteristics:

COMPATIBLE with PRINTHEADS: EPSON.

Viscosity: 8-15 cp
Particle Size: <0.20 u
Surface Tension: 25-35 dynes / cm
PH: 6.5-7.5
Temperature Limit: 65 ° C.

 

ah and I am using acrorip 9.03

 

yes the uv unit and just next to the print head

 

https://ibb.co/746NhQG

 

I don't think so because when I put less white ink the result is good, but the color is a little less colorful than the original image https://ibb.co/h9cR3n8

 

ok thank you very much i will try to change ink