So I've encountered some wierd bug that only happens when I'm trying to set trade route to a specific island.
I've bought Season Pass 3 (I already had 1 and 2) and decided to play a campaign with all the DLCs I have. It was going smoothly for awhile (some citizen quests didn't start, but restarting the game usually fixed that), but then something strange happened: I captured that one island (eastmost one on the screenshot, I'm playing green) from AI with an assault, tried to set up trade routes to it, but the trade route point ends up somewhere in the ocean instead of island's harbour (green route on the screenshot is the one you expect and also the one showed on the map, red one is what you actually get). Ships get stuck there, can't load/unload and eventually are beign attacked by enemy AI or pirates. Charter ships to that island just never appear, or I couldn't find them, but the goods aren't transferred.
I tried it with different routes, different ships and so on, but it looks like this particular island's coordinates are bugged somehow. It is possible to continue this campaign without using this island, but it'll be a bit complicated since exit to the Old World is located at South-East of the map.
Searching the forum and reddit for similar bugs didn't give any fruits, but maybe I wasn't trying hard enough.
I believe examining the save file will give much more information on this bug, but the forum doesn't allow me to attach it. Please let me know how could I send it to the developers.