SSRS Report showing different output for different users

When outputting an SSRS report, some diagrams are displayed differently for different users. One of them shows different values, as shown below:

User1:                                                                                    User2:

For some users the display of the characteristic value in the diagram is missing. In the following diagram the same data set is displayed. Only with another user values are missing at once:

User1:                                                                     User2:

For one user, among others, a diagram is not displayed at all.

All users have the same security roles.