I'm playing on Bungle Wasteland and did not realize I accidentally accepted a sponsorship I already had, until my other sponsorship showed I hadn't placed the item even though I just finished decorating the sign. Restarting didn't fix it but when I restarted it allowed me to get a third Mudbury sign. Deleting all the items including the duplicates has fixed the problem for now, but I don't know exactly when it decided I didn't have the items already placed. I can explain how I got the third Mudbury sign.