Test the equipment anyway, because it is free and it is cumulative. Coffee oils build up in grinders, jars, mesh filters and especially rubber gaskets, and once they go rancid every batch tastes burnt regardless of the beans.
Strip the cold brew maker down properly including the seals, clean the grinder burrs and hopper per the manufacturer, and replace cloth or paper filters rather than rinsing them. Mine tasted like this for a month and it was the burrs.