no error or warning message in console, i could just put the photo in this issue, it's so weird. -XP
my first account (default):
my second account (admin):
i just stop and restart my server and this bug exists. the first account logging in the server is default, and the second account logging in the server is admin, then the bug appeared. i changed the order of account login, then i found the account which logging in the server later could see 2 npc's name. the id of the npc is 2, 1 and 3 has not found a bug like this till now.