It's been happening to me (only) for weeks, i'm not capable of using my party items such as cards shuffle. After I pick the item, when I press the card shuffle button it won't activate regardless of the area i'm in. The same goes to firework and magic wounds etc.

Edit: I thought they don't work regardless of the place, they seem to be working outside the pixel buildings. I couldn't use them in battlae arena/towers eventho my friends were able to use them? The card shuffle is an example. Any reasons why?