Yes, this difference is intentional. In the dashboard, we always display the live measured value of your system.
In the PV forecast, however, you see aggregated values for each full hour. The data point for the current hour already represents the forecasted total yield for that hour. If we were to display the actual intermediate value here (e.g., the value at 11:05 AM), the point in the chart would constantly change its position.
Additionally, the forecast is cached hourly to avoid constant reloading. This means that if you open the view at 11:05 AM, for example, the displayed value for the eleventh hour remains unchanged until the beginning of the next hour. Therefore, the values in the forecast are not live, but fixed for the current hour.