Dark LOD tops on Purpur server

I have a Purpur server (1.21.4, plugins: world edit, better structures, distant horizons 0.9.0, chunky, datapacks: better structures datapack, tectonic for world generation) and I pregenerated chunks with Chunky plugin, then added Distant horizons plugin and pregenerated LODs from the existing chunks. Everything worked, but when I visited some pregenerated LODs and then teleported a few thousands blocks away there were weird dark chunks. And the more I played, the more of them appeared. I dont think the problem is caused by my client side mods like Sodium, Iris, Lithium, because I tried playing without them and the problem was still there. Turning off shaders or changing graphic setting dint help too. Other players on the server have the same problem and in singleplayer everything is ok, so I think there is some problem in communication between server and client when client is asking for LOD updates. I asked ChatGPT and it told me, that there is some problem with Purpur and Paper, because they are calculating light differently. The only fix I found is teleporting up in the sky, pregenerating all chunks and then turning off distant horizons on the server completely, so there are no chunk updates. This stop the chunks from turning dark, but when I turn it on again they all get corrupted. So all players have to load their LODs before the official server launch and then I would turn distant horizons off on the server. But new players who join later will not be able to get the LODs from server. Is there a better fix for this? Other things I tried (nothing worked): - changing some settings in the mod on client side - changing the config on server (and pregenerating new LODs every time) - reloading the LOD by going there and removing/placing blocks (this just generated more dark chunks around)