Victor, your cell is "current limited". All the cells of this type are actually current limited, but it usually occurs at a value much higher than typical CCR ranges (greater than 1.6 but usually more) in a good/working sensor. As the fuel is consumed this limit comes into normal diving ranges and is one of the common failure modes. This is easily checked by spiking the O2 levels either at the beginning, during, or end of a dive (pre-dive if it is as low as yours or higher values in a pressure pot). Once a cell is said to be limited, it will not typically start working normally again, but a working cell can develop this condition at any time or gradually as it ages. That's why there are arguments about when/how to spike O2 levels.