If you have enabled Smart Modeling, the insert icons are displayed under the following conditions.
Enough space
There must be enough space to arrange Insert icons around an object symbol. Therefore, the model display must be large enough to display
Insert icons in the model in addition to the objects.
Thus, Insert icons are displayed when Smart Modeling is enabled and the model display is equal
or greater than 30 %.
Permission to use a connection
The user must have the privilege to use the outgoing connection of the selected object.
If a user does not have the privilege because the used filter does not allow the connection,
the Insert icon for the corresponding direction is not displayed.