Milhouse Balloon Archway Issue

I just unlocked the Milhouse Balloon Archway. I then placed it in front of the Van Houten house and as I moved away to another area I got the Bart screen. Once I got back into the game the Archway was nowhere to be found, either on the map or in my inventory and I’ve logged in and out and synced a few times to see if this corrects it but the Archway is still missing. Anyone else having this problem? If I’m not the only one then hopefully there’ll be a patch to rectify it.