DIAGNOSIS Stagnant water and mineral buildup in the internal lines and evaporator plate are contaminating the ice.
FIX Run a full vinegar cleaning cycle, but let the solution sit for 30 minutes instead of 15. Use the 'Clean' function (hold Power for 3 secs), and let the entire cycle complete. Afterwards, run two cycles with fresh water only to flush.
IF THAT DIDN'T WORK For persistent taste, use a commercial ice machine cleaner like Affresh instead of vinegar. Follow the product's instructions precisely, as these cleaners are stronger at breaking down biofilm.
HEADS UP If you're not using the machine daily, always drain it completely and leave the lid open to air out. Stagnant water is the root cause of bad-tasting ice.