Game mistaking art uploaded from gallery as Custom Content

Game mistakes art from gallery as custom content and because of this reason, will not upload builds to gallery, EVEN THOUGH game will claim it has been uploaded.  If i only use art from the actual game itself building loads to gallery without any issues.  One of my builds was chosen for a 'sparkd challenge', I was so excited, the next morning when I checked to see if anyone had liked it enough to download to their own library, it was gone! This build had A LOT of gallery art in it! Friends even tried finding that build on their own computers to no avail and of course hashtags and item names, were checked also. That was the first time this happened, it was early July. It happened twice more after that with different builds with gallery art.  Now I have  been using only the art in game and it doesn't occur.  Could you please look into this matter?  By the way I have some cool ideas for new Sims4 kits, I am unfortunately, not a 'maker' but have a BA in fine arts and great, original ideas.  Thank you and sul sul!  Batavia544 a.k.a Swaddledog a.k.a. Furioso544