The bug
When you set a server icon, and the client receives and stores it, then remove the server icon, the client doesn't remove its stored icon. However when you change the server icon the client correctly updates.
MC-34756
Server Icon not removed when the server side removes it
Open
5
(Unassigned)
Confirmed
UI
icon, server
Minecraft 13w41a, Minecraft 13w42b, Minecraft 1.7.4, Minecraft 14w05b, Minecraft 14w06b, ..., 24w20a, 24w21b, 1.21, 1.21.5, 1.21.6 Release Candidate 1
Retrieved
Confirmed.