Which model of Latex is this?
Assuming that it is running Yellow and Black through one head, as was the case on the L2 machines, you are seeing cross-contamination on at least one of the YK heads. I would suggest that you run a nozzle test print (Ink Menu > Image Quality Maintenance > Clean Printheads > Test Print), and see which head is causing the issue.
You can then attempt to run one or more cleanings on that head color, or simply replace the offending head(s). Depending on the amount of ink that has passed through that head, it may be a warranty or non-warranty replacement.
If you have to buy the head, the cost is less than $100 and you're back in business in about 10 minutes after replacing the head (the printer will calibrate automatically after head insertion).