Unable to build Santa's Workshop

Same issue on my iPhone 11. Put it in storage when I no longer needed it. It is now greyed out with a message saying "Maximum number built".

I found the workshop! Somehow it ended up in Green Valley. I have no idea how it got there as it had been in storage since last Christmas. 🤔

Check to see if it is in one of your other cities. Mine was in Green Valley. I have no idea how it got there.  It was tucked in with some houses. Weird.  🙂

So, with the help of a helpfully insistent EA support person I found the workshop in a remote part of my small capital city where I had apparently moved it. The reason I could not initially see it is that it looks different from the others. By this I mean that when you tap on the factories icon all other factories are highlighted with an 'i' on them that is highly viisble. Not so with Santa's workshop because it is not upgradeable.

Mine is also greyed out.  I've checked all my cities and cant find it.