controller.loadRecords calls onRecordSelection on relation

I try to debug a problem and I saw in the debugger that controller.loadRecords( dataset ) (contains only 1 record) calls onRecordSelection on the related form, but not onRecordSelection on the main form. Is it not called on the main form because it caontains only 1 record?

I don’t understand why it happens. Maybe somebody could this explain to me?

i guess the main form already did have 1 (or more records) and the first record was already selected? So UI wise the selection didn’t really change?
But i agree that this is a bit weird if that is the case, because another record is selected.