The devs are starting to hear about it more - as to what they have planned, I don't know.
The CAUSE of this is there is a strip of subserver on each side of the line, that your ship cannot enter into. Its width is based on the LENGTH of YOUR SHIP. And, you can't leave your ship if the destination is across the line.
You can get closer to the server line on a rowboat than on a dragon boat, than on a Tokuno HS ship, than on a Britannian ship.
Prior to Rising Tide, this was mostly a concern with SOS - as if you were doing an SOS from a larger ship, you might not be able to get close enough to fish it up. I had to go out on a rowboat to fish one up near a server line off Britain, because my Brit ship couldn't get close enough.
Apparently the pirates and merchants can get scuttled in that area, while you can't reach them (as they are effectively on the server line, or too close to it for the game to figure out which side its on). Whatever fix is done long-term for the pet disappearance bug (as opposed to any quick fix that they might put in) might affect this as well.