I fail to understand. There is no strait province anywhere close by. Only three exist on the whole map, 2441 is certainly not one of these.The Naples port may suffer from the same issue as the Gibraltar port. Trapped fleets if province is taken while they are in port.
Just correct it, I have never seen a problem with the arrows and it sure looks weird that fleets skip the province border when going to sea.
... Somewhat hard to spot, as a player typically has no reason to use Naples as a port, but now that we know, no reason to leave it be.
Incidentally, Naples is also (marginally) more useful with seazone 2441, as there are already two other naval bases bordering 2439.