Pile of units not recognized in inventory

I’m not sure when it happened, but I lost the slot for pile of units in my inventory. I still have some in my condo as decoration, but I tried unlocking one of them and putting it in my inventory, and poof it was gone, no slot added to show it being there or anything. I’ve already uninstalled once and verified cache twice and no luck so far. I hope I can get some help on this.