The Bug:

Players are kicked from server environments due to chat message validation failures when attempting to type in chat after having previously altered chat settings.

Just to clarify, when this issue occurs, nothing is logged in either the server or game output console.

Steps to Reproduce:

1. Get two players and label them "Player A" and "Player B".
2. Start a server and get both players to join it.
3. Get "Player A" to type any message in chat.
4. Get "Player B" to navigate to their chat settings and set "Chat" to "Hidden".
5. Get "Player B" to attempt to switch gamemodes by using F3+F4; they will be unable to because of MC-167224.
6. Get "Player B"  to navigate to their chat settings once again and set "Chat" to "Shown".
7. Get "Player B" to type anything in chat.
8. Take note of how "Player B" is kicked from the server due to "Chat message validation failure".

Observed Behavior:

Players are kicked from server environments due to chat message validation failures.

Expected Behavior:

Players would not be kicked from server environments.