Hello: In reading through this conversation, things aren’t adding up. Is there a chance that there is a second anode in the hot port? Removing the anode would have eliminated the odor if it were the normal rotten egg odor. You also have a charcoal filter. If that were infected with bacteria, it could be a problem. Is the softener bypassed so no water is flowing through it? Anything in line that could provide a breeding ground for bacteria is suspect.