France not attacking my ship?

I'm trying to lure out the garrisoned ships inside Corsia's port but whenever I order my ships to enter the red zone, they dont come out. Is there any other way I can get them to come out? Thanks.

Land a militia unit (or some unit you can stand to lose) and push them out of port while its blockaded.

thanks! worked!

Sometimes send in a very weak unit into the ZOC with your main fleet on the edge of the ZOC and often they take the bait.

I had the same problem with a spanish fleet the militia thing works great, until the poor souls are stranded on the spanish mainland.