If this has been posted before, I apologize. When all the consumables slots are full and you try to use a consumable, that consumable will not work. It will reduce the amount and have a cooldown, but it will not activate the consumable. Example: Consumable inventory is full of items. I use a Heavy Ammo Synthesis which is part of a stack of 10. It reduces the number to 9 and there is a cooldown for 5 minutes. I check my ammo and it did not replenish it. Once there is 1 empty slot in the consumables inventory, all the consumables work. It's not just synthesis' that it applies to, it's all consumable that are used will not work if your consumables inventory is full. Wanted to let you know if this hasn't happened to you all yet.