Not existing objects in association table

Situation: In the domain model I have two object, A and B. A is owner of a - association with B. Problem: In the association table I have more rows than objects of both A and B. This is not a problem, because multiple combinations are possible. However, not all referred objects in the table actually exist. Question: How (and under which circumstances) is this possible, since Mendix keeps the associations up-to-date when deleting a specific object? Caution! No manual changes are made directly on the database!
1 answers

Have had this situation once before but could not find the cause of it. To restore you could try to make a microflow that restores the association.