This started happening since 3.2 withs ervers we host. Hardware is very capable, it server which coud stream Tv for hundred clients, when used so.

When connecting though certain backbone providers, after some time, if player stays in same region (e.g. for mining, building), on next login End of stream happens. Monitoring connection with WireShark shows that client and server stop getting packets properly, as disconnect happens prior to large network burst generated by server.

End of stream error happens in few seconds after login, so it possible to move (though world around seems frozen and doesn't react). Movenet happens server-side too, so player can escape "hazard zone" in several login attempts.

reseach shown that it never happens if player surroned by ocean biome chunks. Work , and quickest reason of connection "dying" are jungles.
After some time, if no players visit that area it becomes "login-able" again. Changing difficulty to "peaceful" , thus killing all hostiles, doesn't matter.