When issues are imported, Solibri builds a new viewpoint internally. Any components referred to from the viewpoint which are not present in the currently loaded models will be discarded, and will not be visible in the viewpoint. This can be the case when you are not using the latest models.
⚠️ Attention: Please make sure that you always have the latest models loaded before importing new or changed issues. Updating the models after the import will not resolve this issue. You will need to discard your presentation and import the issues again.