Problem with plot on V4.4-3

I had installed FreeFem++ V3 on Fedora before and it worked well. When I made the plot, a new window opened showing the figure.
Now I had updated and installed V4.4-3 and there is a problem. When I make the plot, no new window appeares any more to show the firgure. I can only use the plot(ps=“file”) to save the figures and view them.
What can I do to make the plot reopening a new window to show the figure again?
Thank you very much!

Which FreeFEM do you use? Binary or compiled package?
In compiled case, you can read this post Compiles fine but no graphics in Freefem++ executable (V4)