Basically the scratch results screen lets you use any ticket items you get immediately before leaving the results.
If you do a 12-set scratch and get multiple of the same motion (MTN) ticket for a motion you didn't have registered before, using any of them in the results screen will consume all of them.
Instead, exit the results screen and use one of the tickets from your inventory afterwards. This will retain the duplicates.
Edit: Now announced on Global too.