When the map restarts in zombies after a game ends, clients experience several different bugs that are only clientside. An example is the no sound bug, which is where clients have no sound except music. These are fixed by leaving and rejoining the server. I always found leaving and rejoining after a server ends being a pain which is why I spent some time making a workaround for server owners:
https://github.com/JezuzLizard/Public-BO2-Mods/tree/master/MapRestartWorkaround
This mod also fixes doing a map_restart or fast_restart from the server console.
Basically, the mod calls a map_restart() when the game ends instead of the normal map_rotate and this fixes all the clientside only bugs for all clients every time. Doing this caused some bugs which I also had to fix.
The bug where the game hangs at the blackscreen when there is more than 1 client in game is fixed, and the invisible players who can't sprint should be fixed as well.
If you experience any bugs using this mod tell me I will try my best to fix them as quickly as possible.