Sawgrass SG500 cloudy prints

Hiya! I’ve had my SG500 since September. Most of what I do are wallet cards with photos so I haven’t had this issue until now. I’m trying to print an a4 size aluminium print with a mostly solid shade of blue, and the prints are coming out cloudy. I believe it’s an issue with dithering. I’ve tried it on 0.5mm, 0.7mm, and Chromaluxe metal from sublimetals all with the same result. I have a uk press heat press and have tried all sorts of variations in pressure, time and temp from about 120c all the way up to 220c and 30 seconds to 120 seconds. I sent the file to someone else with an SG500 and they had the same results on their adkins press so I think I’ve ruled out my heat press as the issue. The original file is a vector format that I’ve placed in a PSD to print.

Any recommendations on how to fix this? And if it is an issue with the printer which I think it is, any tips on getting sawgrass to give me a full refund as it isn’t fit for purpose? (I bought it from MDP back in September).