legendary fish bug

[kangsungyu2]

I've caught all the legendary fish, and all 13 are showing up in the compendium. However, the legendary Gar is not marked as caught on the map. How can I resolve this issue?

[LILI]

You ran into a very old map glitch ! (+6 years old)
Gar and Muskies are often the culprit it seems...
https://www.reddit.com/r/reddeadredemption/comments/9tttyy/legendary_fish_glitched_not_crossed_out_on_map/

It happens when several things happen, like:
- You caught the legendary but something external cut the progress, such as an attack
- you slip, or your horse bearing the legendary fish slips in the water or fall, and you let loose the fish after catching it: it seems that recovering again the fish - even wrapped for load - in the water, makes a data/update conflict somewhere: once crossed, the map can be reset with an uncrossed state.
- you had a crash before the game finished registering all data, the map data being the last to be updated: compendium is updated, then the mission log, and map last.
- You used alt-tab or a printscreen during the time the game was recording the event and your system had a memory glitch (very very rare, but it happened on older systems)
- you reloaded a saved game with some corrupted data, not updating correctly the map
etc

In short, fear not.
This map is essentially cosmetic ; if the log for A Fisher of Fish AND the compendium for Legendary fish are correctly updated in number, mailing, type of fish found (with the data "Total Progress 100%" + "Caught 1/1"), so you are fine, you can finish the mission.
Boring, but there is still no legit solution other than reloading a manual save before you started fishing this legendary, which is often not done without loosing tons of things already done.