Description:

Certain earlier-game ships receive a "lost at sea" debuff when they end their turn in the ocean. If they end the next turn with this debuff, they get destroyed. In order to lose this debuff and survive, they must enter coastal waters the following turn. However, when they do so through splitting an army, not movement itself, the debuff persists and the ship must leave and re-enter coastal waters that turn or be destroyed.

Steps to reproduce:

Have a fleet of 2+ early-game ships, park them in the ocean, end turn. The fleet will gain the "lost at sea" debuff. The following turn make sure they are on an ocean tile neighboring a coastal tile, select a single ship from the fleet, and tell it to leave the fleet by moving onto the coastal tile. It will maintain the debuff.

Expected behavior:

The debuff should be lost regardless of the method one uses to enter a coastal tile, upon splitting the fleet and entering a costal tile the debuff should be lost.