good question. not sure what yeast you used, but my notes say mine stuck at 1.006, Not too far off yours, but still 1.010 would be nice. I'm assuming you corrected for temp since it would take quite a temp difference to influence 4 gravity points, it would be noticeable. that being said, mine was at 1.006 before the berry addition, and then again after, even after restarting fermentation with the berry addition.
I have a batch in progress that i'll be adding berries to in a week or two. I pitched s-04, and I'll let you know what gravity I see pre and post.
I will be upping the berry quantity on this one. looking for more colour and a more noticeable berry character.