Maybe you are really deleteing the child when you thought you were deleting the parent. Certain layout designs can create that mistaken impression. Other explanations are also possible.
Can you describe your layout and what you are doing to delete a record in more detail?
Three tables in question:
Leads (ID) ---< (ID_leads) Lead_Sets (ID_Sets) >--- (ID) Sets
The layout I am deleting from is based on the leads source table.
I am trying to make sure that if a lead gets deleted, the child Lead_Sets records remain. I am deleting using the native delete button in the status bar.
What does the confirmation message read when you click that status bar button?
If it reads "permanently delete this entire record?" you are deleting the parent record.
If it says "Permanently delete this one related record?" you are deleting a related record from the portal--which could be how your records in the Join table are being deleted.
The difference is what part of your layout is current at the time you click that button.
"permanently delete this entire record?"
Then the only way records in the join table could be deleted is if you have "Delete related records in this table when a record is deleted from the other table" in some relationship somewhere in your relationship graph that links these two tables. If you have lots of table occurrences to the same data source table, you'll need to check any of them that link these two tables.
Otherwise those records in the join table will not be deleted.
That's what I thought. So I guess what ever I am missing is something under my nose. I just have to find it. Thanks Phil.
If you want a second pair of eyes looking for that missing detail, upload a copy of your file to a share site and I'll download a copy from there to take a look. If it's too senstive to do it that way, I an also use a private message to send you an email address to which you can send a copy.