Scoreboard teams and objectives randomly deactivated or deleted after re-opening a world

Some of the scoreboard functions are not working.

I was building a map and just added some command blocks, which let you join a team.
I added some objectives and gave them setdisplay options.

After I joined a team, I reopened the world and then I instantly left the team.
One objective with the display slot ''sidebar'' lost his display options and some other objectives were completely removed.

1.Adding team: red Red, then joining it
2.Adding some objectives
3.Joining the team red
4.Adding one objective to the display slot sidebar

5.Reopening the world
6.Not in team Red anymore
7.Two Objectives are deleted
8.One objective is not in the sidebar anymore (but still existing)