Situation:

I have some iron in my inventory and want to grab some more out of the oven.

When I grab iron from the oven with my Xbox Controller pressing (Y) I can see for a second that the iron in my inventory gets more and then its right back to the status I had before. 

So the iron i grabbed from the oven just vanished. 

However when I manually grab the iron from the oven with the joysticks and put them into an extra place in my inventory the stay put. After that I can combine both and it works.