Multiple entries en oc_cards table


for quite a long time (at least since oc 9), when one of my users try to share with others, after writing something in the box, my NC shows multiple entries for the same user, and only the 1st one is actually working.

After some research I’ve seen that this is because there are multiple rows for the same user in oc_cards table. I’ve tried to delete all the rows but the first one (the one with the lower id); after this I only find one entry for each user, but sometimes it’s the working one, and some others not.

Is there any way to know which entry is being used? (I’ve thought about the lastmodified field, but I’m not sure about it)