Hello -
This may happen if you are using a hierarchy and reconciliation.
In the modeling view you see information before your hierarchy is reconciled. Basically it shows you which models were considered and which model was chosen.
In the forecasting view you will see the impact of running reconciliation - which basically makes sure that the numbers add up across a hierarchy.
You can overlay the forecasting model plot by selecting "View -> Edit Forecasting View Properties" and check "Selected model":
This will allow you to visualize the impact of reconciliation.
Thanks,
Udo