In a more direct answer to your question
Having checked the boxes to sent QSLs to LoTW I assume L32 puts a Y in the sent LoTW column (although on the L32 help file it notes the N is not actually changed to a Y)
So I assume the ADIF file sent shows all QSLs sent to Lotw.
The report back from LoTW says all QSOs do not have the sent to LoTW QSL.
Is that a coherent answer?