Been an issue for a long while which feels very much ignored and happening on multiple gaming devices, for me it's on the Xbox One. Large portions of discovered map completely disappears either after logging out of the game and back in, or when you go in and out of a volcano. It ends up looking like a massive line down the map. Sometimes re-logging will just change the area which disappears, so the missing locations have to still be in the save files, just not loading up into the game. This only seems to happen after discovering large areas of the map, days playing don't seem to affect it. Unfortunately can't get my picture to upload on this site. Hoping the issue isn't going to be ignored as I've seen this complaint made on various other sides dating from a few years ago. Is it still an ongoing problem for others or am I just unlucky?
Exact same thing has been happening on the Xbox one. Will admit it's pretty irritating. I try re-logging into the game and all it does is either change what large area of the map is deleted, or it'll do nothing, still leaving me with a large deleted area of the map. If this was a free to play game, I wouldn't complain much, despite the sizable off putting issue, but it's just more frustrating after having paid for it, and still having no sign of the issue being fixed.