1.8-ONLY local cache issue with filled_map render

Dear community,

I am asking for quite a technical bit of help here. I am working with MapRenderers, and doing a basic 1.8 plugin for my 1.8 ONLY server (consider no protocol hack plugin being used, since the issue is happening even after uninstalling it), that shows to a player the location where he can run away from the danger.

Here is the renderer class: https://pastebin.com/6ihGG7sL

And here is the way I give the map to the player :

Code:

Code (Java):

   public ItemStack getMap(Player player) {
       MapView view = Bukkit.createMap(player.getWorld());

       for(MapRenderer r : view.getRenderers()) {
           view.removeRenderer(r);
       }
       view.addRenderer(new AreaRenderer(endPoint));

       ItemStack map = new ItemStack(Material.MAP);
       map.setDurability(view.getId());

       ItemMeta im = map.getItemMeta();
       im.setDisplayName(ChatColor.GREEN + "Carte de survie");
       im.setLore(Arrays.asList(ChatColor.GRAY + "T'indique l'emplacement de la",
               ChatColor.GRAY + "safezone, là où la corruption",
               ChatColor.GRAY + "ne t'atteindra pas"));
       map.setItemMeta(im);
       return map;
   }

As you can see, the code itself works well :

Image (open) Image (close)

The only issue, though, is that when the server restarts and reinitialize the world (hence the players data remotely) with a rough rm -rf <map-folder> && cp -r <clean-map> <map-folder>, players getting a fresh new generated map with the same damagedAmount that they had before have it frozen. The cursor isn't moving, like the renderer isn't rendering anymore. There is no server-side error, nor client-side error.

Disconnecting from the Minecraft client solve the issue (but I won't ask my players to do it at the beginning of each game haha..), and getting a map with another damaged value than the previous one solve it too (but the only mean to give a defined "N" damaged value to the map is to create "N" MapView before, which is not a solution).

----------------

The main reason that comes to my mind is:
Minecraft is somehow caching locally player's serverside data, which is useful for resource packs and, probably... custom maps, since they can include very large 128*128p buffered image *optimization intensifies*. And the fact that the world's cache is cleared before the start of every game would cause synchronization issues. -> The problem doesn't appear in LOCAL 1.9+, but does appear in LOCAL 1.8, which leads me to think that the issue is indeed located in the local player files of legacy versions, cleared after a launcher session restard. Any way, for instance, to clear user's current server cache locally?

Does anyone have a strong understanding of that particular topic? Any help would be highly appreciated!

Thank you very much for your time, wishing you all a great day

@timtower this might be a weird bug from my side, but could you please release that publically? I don't see the "waiting for approval" anymore, but I still have 0 view on the thread. As you can see: this new thread is now protocolhack-free compliant

Best regards