longshore current - Forum - Delft3D-Old

Dear all, we are modelling a coastal region. Our domain has three open boundaries (see attached figure 'current NW-SE') with:
- an astronomic water level condition at the offshore boundary;
- two Neumann conditions at the cross-shore boundaries.
We want to add a longshore current representing the Western Adriatic Current. We tried to impose a current time series on the NW cross-shore boundary and leave Neumann on the SE cross-shore boundary. The current varied from 0.3 m/s at the offshore node to 0.01 m/s at the shoreline node. The current propagated well inside the domain and stabilized after around 18 hours (see attached figure 'current NW-SE') . When we tried to switch the direction of the current, imposing the same current time series (with negative sign) on the SE cross-shore boundary and leaving Neumann on the NW cross-shore boundary, the current did not propagate (see figure 'current SE-NW' . 
Which could be the cause of this error? Any suggestion to solve our problem?
We also attached the grid and bathymetry files.  Thanks in advance.