Your save is not lost.
It is missing one state.
Separate the kill, the quest item, and the NPC hand-in. That usually reveals why the next radar contact has not appeared.
Where are you stuck?
Pick what your save currently shows. The answer updates without changing your game files.
Beat the Spider Crab and buy the radar
Finish the Lighthouse keeper’s opening quest, defeat the Spider Crab with the Empty Beer Can bait, collect the keys, then purchase the boat radar. The Forest appears as the green contact northwest of the Lighthouse.
What this How to Fish next-step solver checks
The island route is a sequence of states, not just a list of bosses. First, you reach the current location. Then you complete the encounter, retain the progression item, and deliver it to the correct NPC. The solver asks about those states separately so it can distinguish an unfinished fight from a missed hand-in.
At the Lighthouse, the important state is different: the Spider Crab opens access to the keys, boat, and radar rather than producing another standard trophy hand-in. The Forest route centers on the Giant Piranha skeleton. The Desert uses the Pufferfish fin. The Rocks use the Albatross head. The Volcano is the final normal contact, so there is no sixth standard island dot to reveal.
Why old routes can disagree
Patch 1.0.5 closed a sequence break that let players travel to locked islands. A speedrun or Bean guide recorded before that patch may skip a state that the current build requires. The solver follows the patch 1.0.9 route and links to the relevant guide rather than claiming an old skip still works.
If the item disappeared
Do not start by deleting the save. Patch 1.0.6 changed when the game writes data, and patch 1.0.9 only said save corruption was "hopefully" fixed. Exit normally if possible, copy the entire save folder, and then use the save-disappeared guide. Repeated loads and saves can overwrite a recoverable state.
The solver never reads or uploads your files. Its answers are driven entirely by the four controls above, and its share link stores only those choices in the URL.