I found a bug in a mode

Hello mojang, recently I downloaded a mode from the minecraft store called (Dragon advance). I download the world, I fit into it, all of this goes wonderfully. I get my dragon and I make it grow I equip it with a saddle and armor and there is a second item called an (upgrade) but I am trying to install this item in the inventory of my dragon but it doesn't work I already recreate a world when I thought it was a simple minor bug and nothing changes and I even restart my console and nothing changes so that item who does not want to enter the inventory of my dragon prevents me from moving forward in my quest that's why I'm sending you this email my username: SparseSpoon2760, my console: Nintendo switch. And I send you a photos attachment. Thanks SparseSpoon2760.                                                                                                                                                               Ps: the screenshot suppost to be à vidéo but it taking to mb for the ticket