Removing any player from a disabled whitelist kicks all players
Steps to reproduce:
/whitelist on
/whitelist add username
/whitelist off
/whitelist remove username
All players get kicked "You are not whitelisted on this server"
Immediate relogin has no issues.
Deep apologies for not providing more information, I did not have the time to at this moment.
Please comment when you get a chance to reproduce this on a vanilla server, and it will be reopened.