Replace Rinse agent door. The old door would not "snap" tightly shut. It flopped a bit and that was enough to allow water in and rinse agent out...... in ONE CYCLE. Poorly designed door is the issue. But replacing it solves the problem. BOSCH NEEDS TO FIX THE PROBLEM WITH A PROPERLY SEALING RINSE AGENT DOOR. This is a design / engineering flaw. The fix is simple. Get a new door -- which should not fail in the first place. Super easy repair. Click it in place.
Pry old door out with a slight twist of a flat end screw driver.