This is very important to understand, and has created much confusion. The developers consider this to be a feature, but we disagree, and would like a different kind of behavior.
This is what happens: Sometimes you are in a position, where you would like to use one of the equipped items to develop new items. Consider that you have five purple generators with no stars. Two are equipped, and three appear as available in the black box.
This makes sense. You have to disconnect an item, before you can use it to build something new with it.
However, say that you unequip one the items, but it still does not show up in black box. Why is that?
The logic here is that the item was equipped when you created a team for Assault. Assault runs are done in a “frozen state”, where the planes and brobots stay in same rank and level throughout the assault run, even if you increase the rank or level. Kind of the same reasoning is used with devices. A device can thus not be used for upgrade, while in assault. In assault you have to old device, outside assault, the device has been used to build new devices.
We understand the reasoning, but think it is wrong:
The situation is actually much the same with planes and brobots, and you are allowed to upgrade them, even if they are used in assault. This will mean that you can have one rank and level of planes and brobots in assault, and different ones in arcade, missions, trials, etc. So it is inconsequential to treat devices differently from planes and brobots.
And even if you accept this, at least we would like the devices to be “set free” when you have completed assault. As it is now, they will be available only when using the reset. Then you are likely to create a new team directly, which has made many people convinced that they never can use the best devices in black box.