I had the same thing happen in the Arts District. I have been playing the same family for a while now and they have been living in the same apartment, attending festivals, outings etc., just fine and then suddenly I started getting street objects moved to my family inventory for seemingly no reason.
Willing to share your save game ?
If so, please zip up this folder: documents\electronicarts\thesims4\saves and drop the file to this Mediafire-Link to upload.
Please make sure to name the zip file with your user name.
