After disconnecting and reconnecting while in The Nether, objectives and teams do not render on the tab list. This is NOT present in the vanilla server.

Here are the steps to recreate this issue (video below) on a fresh server instance:

1. Give yourself OP to be able to execute scoreboard commands as a player
2. Execute /scoreboard objectives add Health health
3. Execute /scoreboard objectives setdisplay list Health
4. Update scoreboard by taking damage or healing
5. Execute /scoreboard teams add Test
6. Execute /scoreboard teams option Test color aqua
7. Execute /scoreboard teams join Test
8. Check the tab list, name should appear in aqua, and hearts next to the name
9. Enter The Nether
10. Disconnect from the server
11. Reconnect to the server

The tab list does not display the objectives or teams anymore. All player names are white.

To fix, you have to enter The Overworld, disconnect from the server, and then reconnect.

VIDEO: