Yes, this difference is intended. In the Dashboard, we always show you the live measured value of your investment.
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 value for that hour. If we were to display the actual intermediate value (e.g., 11:05 AM), the point in the diagram would constantly change its position.
Additionally, the Forecast is stored hourly to avoid having to reload permanently. This means that if you open the view at 11:05 AM, the displayed value for the eleventh hour will remain unchanged until the start of the next hour. The values in the Forecast are therefore not live, but fixed for the current hour.