`NetworkObject` `CheckObjectVisibility` doesn't work on client connection

Description

I want to spawn a networkprefab without any client visibility, first i tried to set no observers before spawn:

NetworkObject.SpawnWithObservers = false;
NetworkObject.Spawn();

this results a spawned object with zero observers, but when a late-join client connects, the object gets spawned on client. The documentation says this is the intended normal behavior, because it only works at the initial spawning.

Then, the documentation says the CheckObjectVisibility will work at both initial spawning and new client connection, so i tried this:

NetworkObject.CheckObjectVisibility += _ => false;
NetworkObject.Spawn();

it did spawn with no observers as the previous approach, but when late-join client connects, it still spawn the object on client.

Reproduce Steps

1. start server/host
2. spawn a network prefab with NetworkObject.CheckObjectVisibility += _ => false;
3. start a client and connect to server

Actual Outcome

a spawned object with visibility always set to false still spawns on late-join client

Expected Outcome

a spawned object with visibility always set to false should be invisible to all connected client and future late-join clients

Environment

• OS: [win10]
• Unity Version: [6000.0.32f1]
• Netcode Version: [2.1.1]

從 NetworkObject 的 SpawnWithObservers、Spawn 和 CheckObjectVisibility 行為著手，比較報告中連結的 spawning 與物件可見性文件。重現 CheckObjectVisibility 回傳 false 時的 late-join 序列，並確認物件在用戶端上仍然不存在；完成標準是可見性也會對未來 late-join 的用戶端生效。